Water nozzle and stream physics (article and dicussion)

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Water nozzle and stream physics (article and dicussion)

Post by SSCBen » Wed Feb 15, 2006 1:45 am

Edit: Note that this article is old. Read the newer Water nozzles and efficiency article for the same discussion.

This is an article I have been writing bit by bit since October. The point of the article is to improve and consolidate the Streams, Effective distance, additives and other articles into one big one. Admittedly, most of the article was written last Saturday, but it's not complete yet despite it's massive length! This article is already longer than the 5000 word Aquabatalicus, and it will not be getting any shorter.

I will be posting this article in installments because I hope to get feedback on certain parts. For this article to be as effective as I would like, feedback is necessary to fine tune each part.

(a note: subscripts don't appear correctly here at the moment)

------------------------------------

Water nozzle and stream physics


Foreward


This text is the replacement for the old "Streams" article I wrote in 2004. Since that time, we have learned a substantial bit more about how to make water guns perform better, and I have neglected to keep my article current. This article serves to describe all known performance enhancements that can be done to water gun designs, with a stress put on the water nozzle and the stream because that is where most of the improvement can be made.

Water nozzle knowledge is fairly scarce, but much has been learned. Several years ago, water nozzle physics were almost considered magic, with Larami being the magicians. This is no longer the case as hundreds of people build their own water guns every year. We no longer turn to Hasbro for performance, we get it ourselves, even better than the best they fed us. This information also still will apply to regular factory-made water guns because the physics does not change from brand to brand, including homemade water guns.

I will not throw around the term "revolutionary" in this guide because whether or not this would be revolutionary is determined by acceptance, not the author. If these methods are to be revolutionary, hype would be unnecessary. I fear that most of these concepts are too advanced to many of my readers, stifling most of any said "revolution." My best efforts will be made to simplify these concepts, but the reader must realize that they themselves are the ones learning and they have to take the initiative if they are interested.

Note to the readers: In this guide, I will use the term distance as opposed to range and the term shot duration as opposed to shot time. Range has an actual statistical meaning and distance would be better used. Shot duration also better describes the statistic. Please note these differences from the typical notation.

Why improve nozzle and water gun design?


What's the point of water nozzle improvements? Performance increase is the main goal. With an improved water gun design, your water gun will shoot a farther distance at the same power.

A greater efficiency is obtained through more intelligent design. No longer are people just building a water gun and hoping that it performs well - they are designing to know that it will perform well.

Some people have congratulated me on writing guides such as this one. The greatest satisfaction I get from this article is knowing that I help people make better water guns. I don't charge money for this information or tell you to go take a class on fluid mechanics. I get right down to the point. Not everyone is smart enough to handle a college level course and you don't have to take one to know how to do most design improvements.

Fluid mechanics background information


Before you can proceed further in this guide, you must be comfortable with basic fluid mechanics terms. If you do not fully understand there terms, you simply will not be able to understand anything else described in this guide! You aren't saving yourself time by skipping this important section, you are wasting it! I will present these terms in plain English, mostly because I don't know them any other way myself.

I assume that one who is reading this guide has a basic understanding of how a water gun operates and the parts of a water gun. If you do not have that knowledge, I would recommend the HowStuffWorks article on the subject as it is written very well and has easy to understand animations. Alternatively, disassemble a Super Soaker water gun and figure out how it works from there. In the future I likely will be writing my own guide on how a water gun functions, but that project is not high on my list of priorities because of the excellent resources already available.

Pressure is essentially how much force is being used to eject the stream from the nozzle. The pressure source is the pressure chamber. There are many different types of pressure chambers, such as rubber CPS systems and air-pressure systems. Each system has it's advantages and disadvantages that I will not cover in this guide. When I refer to power or pressure in this guide, I am speaking of the force used, almost analogous to horsepower in cars. A pressure drop-off is attributed to most air pressure systems excluding constant air pressure. CPS systems such as rubber CPS, constant air pressure, and spring powered water guns have a much more constant performance. The drop-off or lack of drop-off can be seen in a water gun's output curve, which will be covered later in this guide.

Viscosity is the tendency for a fluid to stick together. Certain fluids, such as glycerin, have a higher viscosity than water. Viscosity varies by temperature, but as a general rule viscosity improves slightly as a fluid gets colder.

The size of the orifice is essentially the size of the part commonly called the nozzle. The size of the orifice determines much of how a nozzle will perform. For water to exit a smaller hole, it must accelerate. For that reason, smaller nozzles typically have a greater velocity than larger nozzles at the same power. Orifice size determines many things, such as output and stream velocity. Smaller nozzle orifices will have a greater velocity and lower output, while larger nozzle orifices will have a lower velocity and higher output.

Drag on the stream is caused by the stream hitting the air. Depending on the stream cohesion (a combination of the viscosity of the stream and how well the stream is formed), stream velocity (determined by the nozzle orifice size and pressure) and the size of the stream, stream break-up will occur a distance from the nozzle. Stream break-up can be described best as the stream breaking into many smaller droplets of water by the drag on the stream. These droplets will fall to the ground prematurely because the stream's velocity was reduced by drag as well. Shoot any water gun and you will see that by the end of the stream, the stream breaks into smaller droplets that hit the ground. Almost never will a cylindrical stream shaped as it exited the nozzle hit the ground due to steam break-up, unless of course the stream only traveled inches.

Flow is said to be laminar when it has a tendency to follow a linear (i.e. straight) path. Laminar flow is affected less by drag because it does not flow randomly. The opposite of laminar flow is turbulent flow. Turbulent flow is less linear and more random. Turbulent flow is measured in Reynolds numbers. Typically a Reynolds number of less than 2000 indicates laminar flow.

The shot angle can greatly affect the distance of a water gun. Due to projectile physics, the range of any projectile including a water stream will be greatest at a 45 degree angle. An angle greater or less than 45 degrees will result in less distance. A higher angle (up to 90 degrees) will give the stream more height, while a lower angle (as low as -90 degrees or 270 degrees) will reduce the height of the stream.

Internal diameter can be best described as the smallest diameter the water must pass through as it travels from the pressure chamber to the nozzle. Internal diameters of all other portions of the water gun are not important because the water will not flow from the pressure chamber to the nozzle in those parts. A larger internal diameter allows for more flow but also allows for more turbulence - internal diameter is a double-ended sword.

Units and variables used in water gun physics


Typically, a mixture of both metric and the English system of measurement is used in water gun physics. The reasons for such a mixture is simple - water guns are used worldwide and people always seem to use the units most familiar with themselves.

Distance (or range) is nearly always measured in feet. Meters are much less common in practice. This choice may be due to the fact that a meter is approximately three times longer than a foot and you will receive a more precise measurement using feet. If meters are used, please use decimals as well to record a more precise measurement. The variable d is used to describe total distance.

Output is how much water exists the nozzle orifice per second. Output is measured in three systems, two of which are essentially the same. I prefer units of mL/s (mL per second) because it provides the most accuracy. The English unit of ounces per second is also commonly used. The traditional system (in units "X") used in water gun physics was used by Larami in the CPS water guns, based upon the output of a Super Soaker XP 70. It is generally accepted that the output of an XP 70 is one ounce per second, or 30mL per second. The conversion between ounces per second and X is very simple - 5X output equals 5 ounces per second. The variable o is used to describe average output over a interval, while oo is used to describe initial output. Instantaneous output would be written as ot, where t is time in seconds.

Shot duration (shot time) is measured only in seconds. Shot duration is defined as the time the water gun is emitting output. The simple explanation would be how long the shot lasts. The variable tf is used to describe shot duration. tf stands for time final, which simply the final instant output was being made. Time final essentially occurs when o = 0.

Capacity of a certain part of the water gun is measured in many units, depending on how appropriate they are. Metric units are the ones I use most often, though some will use the English system of gallons and ounces. Being a smaller container, pressure chamber capacity is measured in mL. Water reservoir capacity is measured in L. The variable vf is used to describe the total pressure chamber capacity when full. vf stands for volume when full.

Pressure is how tightly packed the gas molecules powering the water gun are. CPS systems, with exception to constant air pressure, do not use pressure to operate and will not have a pressure value. Pressure is nearly exclusively measured in PSI (pounds per square inch), though some others prefer bar and atmospheres which are approximately equal. Pressure drops proportionally to the output, and thus output curves are appropriate enough to also be used as rough pressure curves. Pressure is defined by the variable po which is the initial pressure. Pressure at any moment can be given as pt, where t is any moment in time. Final pressure, pf, is always 0.

Velocity is how fast and in what direction the stream is moving. Velocity is an uncommon, but essentially useless statistics. Basic physics can find a position function, and the velocity function can be found rather quickly from that. When used, the variable for velocity is v which also can have subscripts much like output and pressure. Velocity of the water in the position function is different than the velocity of the water exiting the nozzle, and thus there are two velocity functions in reality. The second, even less common, velocity function should be proportional to the output curve.

Nozzle orifice diameter is defined as the diameter of the nozzle, and is a very important number. The nozzle orifice diameter determines many things about how the stream will react, namely the stream velocity, output, and distance. Nozzle orifice diameter is nearly exclusively measured in fractions of an inch, though some people (such as Big Bee from Buzz Bee Toys) do use the metric mm measurement. This statistic is mainly used for homemade water guns, and thus you will use the drill bit size of your nozzle as it's nozzle orifice diameter.

Nozzle orifice diameter is described in the variable n, but you can use subscripts to differentiate between different nozzles if your water gun has the capability to use more than one (i.e. n1, n2, etc.). The square of the nozzle diameter n^2 is much more useful to us, and I will describe why in the section below.

Water gun statistics


To measure your current performance, you must measure the statistics of your water gun. The only way to know that you have an improved water gun is to measure it's performance to see it's performance increase.

Output, pressure, and velocity all come in two forms - average and instantaneous. Average is the common average of the statistic over the shot time or indicated interval. Instantaneous on the other hand is the statistic as a specific time. Instantaneous statistics require Calculus knowledge to use. If you are not familiar with the basics of derivative Calculus, then you likely will not be able to use instantaneous statistics, though you should be perfectly fine interpreting graphs of output, pressure, or velocity. Instantaneous output will be discussed later in this guide.

Capacity is the easiest statistic to measure. To measure reservoir capacity, fill your water reservoir completely and then pour it back out to measure the volume. To measure pressure chamber capacity or pressurized reservoir capacity, charge your water gun fully and discharge into a container to measure.

Shot duration is also another easy statistic to measure. Fully charge your water gun and fire it, starting a timer simultaneously with your firing. Stop the timer when water is no longer being shot out (o = 0). You also can approximate shot duration with an output curve to find mathematically where o =0, but that will be covered in a later section of this guide.

Distance is a very easy statistic to measure, but a tricky one when it comes to accuracy. Many people want this number to appear as high as possible, after all, the higher the distance the better! Do not become part of that crowd. You want accuracy in your measurements. Nearly always a drop of water that shoots several feet from the puddle at the shot. Do not measure to the last drop of water. Measure to the end puddle where most of the water shot is focused - that is your "effective distance." Tape measures and other similar devices are also a necessity when it comes to measuring distance. You can not simply approximate distance, you must get distance correct.

Output can not be directly measured. The average output over the interval from t = 0 to t = tf can (or in layman's terms, the average output over the shot duration) be found by dividing the pressure chamber capacity by the shot duration. Note that the units for output are mL/s, and note that you are dividing the capacity (taken in mL) by the time (in seconds). That is how the unit system works.

Pressure will be harder to measure depending on your water gun's design. If you install a pressure guage on your water gun you will have an easy time measuring pressure. Special nozzle attachments are possible as well if you want to measure pressure without having a permanent pressure guage attachment on your water gun. Remember that pressure is proportional to output - given a constant nozzle orifice size, as output decreases, so does pressure.

Average velocity over the shot duration can be found by dividing the distance by the time it takes for the water to reach that distance. Note again the units here - ft./s - which describe the process being done to get the measurement. Instantaneous velocity could be also be found by making a function to model the stream's motion and then by taking the derivative of the function with respect to time, but that would be too complicated for those who are not familiar with Calculus.

-----------------------------------

The next installment will come once I finish up the nozzle size table.
Last edited by SSCBen on Tue Nov 11, 2008 9:55 pm, edited 1 time in total.

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Post by m15399 » Wed Feb 15, 2006 5:09 am

Great article! Certainly one of the (if not the) best articles on the site! Here are my comments:

internal diameter is a double-ended sword.

So, if my water gun has a larger ID will it get less range or more range (Is one side sharper than the other?)?

Time final essentially occurs when o = 0.

Don't you measure shot time for PR guns to when the output starts to drop off? That's not very easy to judge accuratly, but it would make the tests less biased towards one type of soaker.

Velocity is an uncommon, but essentially useless statistics.

Shoudn't it be "statistic"?

Basic physics can find a position function, and the velocity function can be found rather quickly from that.


Perhaps you could tell us what those are. :confused: Sorry, I haven't had any physics classes, but I've read some of Feynman's lectures (my dad was in a class of his, and is now a physisist... maybe I'll ask him :p ).

Water gun statistics

You already have an article on that. Are you planning on deleting that, too?


I think you should have a compiled short list of the variables. I had to look up a few times to remember what the variables stood for.

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Post by SSCBen » Wed Feb 15, 2006 11:08 am

As I said, this article isn't near complete and I have not posted the article in it's entirety yet! This isn't even a quarter of what I have planned. This is only the beginning, the first few paragraphs in fact.

I suppose I'll post some more since you read it much faster than I thought one would. I'll put in notes in the incomplete areas. Some areas are planned, but not completed as well, so I might post the outlines to see if anything else is necessary.

Thanks for the corrections too.

So, if my water gun has a larger ID will it get less range or more range (Is one side sharper than the other?)?


This depends on the design. I have posted the section on this.

Don't you measure shot time for PR guns to when the output starts to drop off? That's not very easy to judge accuratly, but it would make the tests less biased towards one type of soaker.


I haven't heard of people measuring to the drop-off. I'll mention how to do that in my output curves section.

Perhaps you could tell us what those are. Sorry, I haven't had any physics classes, but I've read some of Feynman's lectures (my dad was in a class of his, and is now a physisist... maybe I'll ask him ).


I'll be explaining this in more detail later in the article.

As for the water gun statistics section, I've already began to write a new article to replace the old one. This seems adequate, so my time would likely be better spent.

Remember, this is coming in installments. More is to come, much more in fact.

--------------------------------------------------

Factors that affect output


Many factors will affect the output of a water gun. Output is defined as how much water exits the nozzle orifice per second. So, let's define nozzle orifice size as the variable n. Output is proportional to the area of the nozzle. We all should know that the area of a circular nozzle orifice is defined as:

pi*(n/2)^2

Much of that formula is unnecessary for our purposes. We only need a unit that is proportional to the equation, and thus for simplicity we should remove the pi and the division by two to be left with n^2. To double output if pressure is a constant, theoretically we only will need to double the nozzle area. n^2 is proportional to nozzle area, so we only will need to double the square the orifice diameter to find the n^2 value for the new nozzle. The square root of the new nozzle's n^2 value will be approximately the nozzle diameter needed for double the output. Finding a close drill bit should be an easy task.

The following table lists common nozzle sizes in fractions of an inch and it's decimal equivalent. The n^2 value also is pre-calculated. This chart should prove to be extremely useful to water gun designers.

(chart not finished yet)

Basic and advanced nozzle features


(needs illustrations before it can be posted)

Linear design


We described turbulent flow in our definitions section as seemingly random, non-linear flow. Likewise, laminar flow was described as straight flow. Turbulent flow is not good because the stream will be affected (i.e. break up) by the random tendencies in the stream. Thus, it would be in our best interests to keep flow as laminar as possible.

The easiest way to create laminar flow is to avoid creating turbulent flow. Turbulent flow that we can reduce is created by turns in pipe. Laminar flow can be created by allowing the water to travel in a straight path from the pressure chamber to the nozzle orifice. Flow must be straight and unobstructed to be ideal. This is the practice of linear design - allowing linear flow, that is flow that follows a straight line.

This practice measure many potential design changes, the largest of which is valve selection. Ball valves are the ideal trigger valve to use by this practice. Ball valves are the simplest valves that allow for perfectly straight and unobstructed flow. In constant, the typically plug valves used in older Super Soaker water guns obstruct the flow, reducing velocity and creating turbulence. Now, the Super Soaker water guns use Max-D triggers which are essentially ball valves. Their choice of ball valves was simple - they allow for linear design.

You can use other valves similar to ball valves and you can modify your system to allow for triggered ball valves. Ball valves are the easy choice because they are cheap, common, and theoretically sound when it comes to design.

To sum up linear design in a sentence: when you look down the nozzle orifice with your valve open, you should be able to see the inside of the pressure chamber.

The term unobstructed later will receive an amendment - some obstructions are beneficial such as linear guidance walls or flexible fibers which improve flow.

4 ways to reduce turbulence


These are four more ways in addition to linear design to reduce turbulence and increase laminar flow. These will go unrecommended by most for one reason or another. I will explain the reasons why these are not typically chosen as turbulence reduction methods in each paragraph.

Reduce the velocity - A lower velocity will mean less turbulence simply because faster velocities create turbulence. Of course, reducing the velocity also reduces potential performance because you will not have anywhere near as much power in the shot. For that reason, this method goes mostly unrecommended. However, remember this if you are getting too much stream break-up from too much power - tone down the power and you will see an improvement. This method is used in many Super Soaker water guns by the addition of performance reducing screens in the nozzles - the screens only reduce velocity to decrease turbulence, though they also may have the less legitimate use of reducing performance.

Reduce the internal diameter - Turbulence can exist easier in larger internal diameters. This is how linear guidance walls (also known as straws) work - internal diameter is reduced into many smaller sections to straighten the flow. Larger internal diameters simply will not straighten the stream. This method will go unrecommended for several reasons. Larger internal diameters allow for more flow, which allows for better performance. Larger internal diameters also allow for less friction, though it really is unknown how much friction affects the water stream. Only try reducing the internal diameter if you have too much turbulence and this would be beneficial. Linear guidance walls always can be removed later. You can try them to see if they help, and if they do not, remove them.

Increase the viscosity of the water - This is a real debate point. There really is no performance downside to increasing the viscosity of the water, typically with additives, though it also is somewhat possible by reducing the temperature of the water to right about freezing. Some people question how ethical it is to use additives to increase performance. Some people wonder if additives are safe to use, either for people or for their water guns. Some people (myself included) are concerned that widespread additive use would cost a lot of money. Additives such as glycerin will be discussed in greater detail in another section of this guide.

Decrease the density of the water - The only way to decrease the density of the water is with additives. Obviously, if the water is less dense (and therefore has less mass), it will have less force to use to create turbulence. This is not really an option because the water will also weigh less, which should negatively affect distance. Further tests in the future may prove that changing the density could have an positive affect in performance, but for right now not much is known.

Maximizing distance through ideal nozzle orifice size


It comes as no surprise that there is an optimal nozzle orifice size for specific water guns. Some nozzle orifices are too big for maximum distance, and some are too small for maximum distance. You must find the perfect balance in a nozzle orifice. As it turns out, these nozzle orifice sizes can add many extra feet to your distance. I was shocked when I discovered the relationship and took advantage of the ideal nozzle orifice size.

No, there is no universal ideal nozzle orifice size (if there was, we'd just tell you that and leave it there). We at Super Soaker Central also will not calculate this nozzle size for you. You must do your own work, and if you do not like the math involved, that's too bad for you!

Finding the ideal orifice size (IOS) takes empirical data, a graphing calculator, and would be greatly aided by the nozzle orifice chart. The process can be broken into some basic steps:

Make 5 or more nozzles of a wide variety of sizes. Make sure to make nozzles smaller and larger than what you believe to be approximately the IOS. Remember to use a fairly small nozzle (such as 1/16" diameter) and a fairly large one (such as 3/8" diameter).

Make a table similar to the one below. The one below is an example which we will use to demonstrate the IOS process. To explain the table, n is the nozzle orifice diameter, n^2 is the orifice diameter squared, d1 to d3 are three effective distance trials, and d is the average of the three trials.

(table will be posted later)

Using your graphing calculator, enter the n^2 column into one list and the d (average) column into another list (I used L1 and L2 respectively). I use a TI-83 Plus graphing calculator, but from what I know most graphing calculators have a regression capability. Using these lists, make a quadratic regression of the list data. On the TI-82/83/84-type calculators, you can make the regression via STAT -> CALC -> QuadReg. QuadReg should appear on the homescreen. Type L1, L2 afterward so the command line says "QuadReg L1, L2". Afterwards, go to Y= and enter the equation into one function. You can use the VARS -> Statistics -> EQ -> RegEQ shortcut to automatically copy the entire regression onto the function. Those familiar with extrema in Calculus won't need to do the remainder of this work to calculate idea nozzle orifice, but read on if you are unfamiliar.

Ideally, you would also set up the stat-plots to get a look at your data. Press 2nd -> Y= to go to STAT PLOT. Set up Plot1 so that the Xlist is L1 and the Ylist is L2. Then go to ZOOM -> ZoomStat and you should get a perfect window on your data. Wait for the graph to plot. The parabola will peak, and to find the peak try 2nd -> TRACE to get the CALC menu. Use maximum to find the peak. The x-value of the peak is the n^2 value of the IOS. You can take the square root of that value or find a close value in the nozzle orifice size chart. Either way, find the n value for that n^2 value.

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Post by m15399 » Wed Feb 15, 2006 11:22 pm

Sorry if you don't want me to reply. I thought that you hadn't written the rest.

To sum up linear design in a sentence: when you look down the nozzle orifice with your valve open, you should be able to see the inside of the pressure chamber.

I know this has been asked befores somewhere, but if the PC's on an APH were slanted 45 degrees back (away from the nozzle), would that make the design more laminar?

The x-value of the peak is the n^2 value of the IOS.

So if I didn't square the nozzle size, and made the x value the size of the drill bit used for the nozzle, would the data be inaccurate?

Thanks, that cleared up some of my earlier questions.

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Post by Drenchenator » Thu Feb 16, 2006 1:36 am

So if I didn't square the nozzle size, and made the x value the size of the drill bit used for the nozzle, would the data be inaccurate?

Actually, I don't really think that it would make a difference, but then again I don't know. I know that Ben wanted to mimic the actual area of the nozzle orifice with the n^2 value. The area of the nozzle orifice is the area in which the water can leave. Since a drilled nozzle will be a circle and the equation for a circle is a=pi*r^2, the area of a circle is related to the the radius of the circle squared. If you substitute d/2 for r it gets (pi/4)*d^2, but still, the d is squared and pi/4 is a constant. I think that that is the reason that Ben chose to n^2 because it relates better to the true area. The data would not necessarily be inaccurate, but this way it relates better to the nozzle orifice area, not diameter.
The Drenchenator, also known as Lt. Col. Drench.

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Post by SSCBen » Thu Feb 16, 2006 1:59 am

Sorry if you don't want me to reply. I thought that you hadn't written the rest.


No, please do comment! That's why I posted it here after all. Whatever you have questions on, please ask! I only want to make these concepts more accessible. Ask anything and everything.

Right now this thread seems enormous, so I likely will edit out the article tommorow and put it in an easier to manage single HTML page.

I know this has been asked befores somewhere, but if the PC's on an APH were slanted 45 degrees back (away from the nozzle), would that make the design more laminar?


Yes, a slanted design as described should provide more laminar flow. Later in the guide I was going to discuss minor loss, but I'll add some bits about that in the linear design part. More linear is better than non-linear. A design like that should combine ease of construction and design with performance. Good idea. I'll be sure to mention that in my article.

So if I didn't square the nozzle size, and made the x value the size of the drill bit used for the nozzle, would the data be inaccurate?


Not necessarily. I used to not square the nozzle orifice diameter, but now after some consideration I know that n^2 is more correct than n for the reasons my brother mentioned - n^2 is proportional to the nozzle orifice area as opposed to the diameter. I really should do tests to prove that n^2 is more accurate. In reality, n alone may get results close enough to the real IOS, and squaring n may only be a waste of time.

Technically the quadratic model is also incorrect, but modeling a normal curve is more difficult than a quadratic curve, so the quadratic curve is mostly correct. The calculated IOS is only an approximation, and I should mention that in my article.

I have been working on a TI8X program to calculate IOS and make output curves, but it has barely been started. I'll be sure to put it on the website once it is complete however. Such a problem will simplify everyone's work. ;)
Last edited by SSCBen on Thu Feb 16, 2006 2:00 am, edited 1 time in total.
Reason: Used a slash instead of a period by accident.

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Post by m15399 » Thu Feb 16, 2006 4:12 am

Good idea. I'll be sure to mention that in my article.

Except you wouldn't be able to fire at 45 degrees for very long, so maximum distance would be hard to measure.

I absolutely LOVE graphic calculator programming! I have about 20 programs on my calculator all written by myself that calculate various things.

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Post by SSCBen » Fri Feb 17, 2006 12:47 am

Yes, I'll mention that too. The article isn't about water gun usability and designing for efficient use, only performance. I should write an article on water gun usability a bit after this.

I also make programs for nearly everything I do on my calculator (great minds think alike?). I used to write a lot of games and I started z80 assembly, but Super Soaker Central took up too much of my time. None of my calculator projects materialized. I now only make programs that help me do work (especially math ones). One of my recent projects also has been working on a graphing calculator website, calc.org, but no work is online yet.

I'll be writing some more of this article tomorrow, so wait for another update. ;)

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Post by SSCBen » Thu Mar 09, 2006 1:07 am

Update to this article coming this weekend. I should be adding the new graphics others have so graciously made and also be adding a bunch of new sections. Look forward to it. ;)

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Post by Silence » Sun May 14, 2006 4:30 am

Not to put pressure (pun intended :p ) on you or anything, but what is the status of this article? If you just need to fill in the tables or the graphs, I can try to help with that, though I don't have a calc-PC link cable.

You might want to refer to the small orifice vs. large orifice debate that we held in "Water cutter." We only reached a partial conclusion, so maybe test results from my PCgH could help you finish such a part of this article. As I've said on numerous (I almost typed numberous :p ) occasions, I'll post thorough measurements when I'm done. Even if PCgHs fail and destroy all the hype they've built, like many unsuccessful projects, it will contribute to science and engineering.

EDIT: m15399's first post points out a spelling error. I understand that forums don't need and won't have perfect spelling like papers will, partly due to the lack of real-time spelling marking as in OpenOffice.org (and Microsoft Word, I suppose). However, if you want this to be truly refined, then I can help with the finer details. If you haven't done so already, store this as a .doc file; if you have, then it probably allowed the word "Foreward," which should be "Foreword." Of course, this is me being nitty-gritty again :rolleyes: . This is a great document.

EDIT: You mentioned something about measuring dropoff...I know Duxburian once mentioned the use of measuring how long a stream of an APH can keep 70% of its original range, and comparing that value to the actual shot time. Then again, you'll only see a real difference between PCgHs and APHs, not between individual homemades of the same type.
Last edited by Silence on Sun May 14, 2006 4:37 am, edited 1 time in total.

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Post by SSCBen » Sun May 14, 2006 2:10 pm

This article will be completed when I find time. When that will be I can not determine however.

The small-nozzle debate will not be included in my article because it simply doesn't hold true. I've done empirical testing to determine the ideal nozzle orifice size. It never is small - it always is moderate for the power involved. That's what joanna and I were trying to tell you in that thread, but it appears that you didn't follow.

Feel free to point our errors, especially spelling and grammar errors. AbiWord, the word processor I use, is good but lacks very good spelling and grammar facilities. The spell check checks spelling, but not so much intention as Word and Wordperfect have come to. So go ahead and refine it as much as you'd like. ;)

You mentioned something about measuring dropoff...I know Duxburian once mentioned the use of measuring how long a stream of an APH can keep 70% of its original range, and comparing that value to the actual shot time. Then again, you'll only see a real difference between PCgHs and APHs, not between individual homemades of the same type.


Lots of people did that in the past actually (most notably the Aqua-Nexus I believe). My methods are completely different and superior. Read some of my summary for a good idea of my methods. I've only been able to do this on very long shots due to the fact that I do not own the correct equipment. This would create a graph displaying output versus time, making the drop-off easy to view.

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Post by Silence » Sun May 14, 2006 6:55 pm

Well, even if I haven't taken you medium-nozzle point to heart (yet), I have stopped arguing in favor of the small nozzle. I really won't be happy with any solution until I see it for myself, but thanks for the information.

You should really try OpenOffice.org...in the past few years, they've ironed out most of the kinks, and after the major redesign a few months ago, the project has put out some really amazing products. Currently, I use a mix of OpenOffice.org and the aging Word 2000, but this summer, I intend to switch completely, as well as switching to Linux. Back on topic, however, AbiWord's lack of a live spell-check explains the rare problems...but overall, the document looks very good.

I don't think it should matter what method one uses to measure dropoff. In (what I believe to be) the plot of the XP 270's range in the AquaNexus page that your linked thread's first post links to, or this page if you didn't follow the first clause of this sentence, one can clearly see that beyond the 70% mark, the range drops off very quickly indeed. Clearly, this is just more reason to switch to PCgHs (and CPHs, I suppose) immediately.

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Post by SSCBen » Sun May 14, 2006 8:52 pm

I have OpenOffice, but I prefer AbiWord for word processing and Gnumeric for spreadsheets. AbiWord does highlight misspelled words, but it does not determine intention as I had said (where Foreword would be chosen as opposed to Foreward). In my experience with Word and Wordperfect, they'll tell you if you make grammar errors. AbiWord lacks a grammar check.

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Post by Silence » Sun May 14, 2006 9:22 pm

This is getting off topic...normally I wouldn't care too much about staying on topic, but since this will be a major article, I don't think there should be clutter in the thread. Are you going to put the final version into an actual article instead of leaving it as a thread? If not, I suggest you move the off topic posts to a new thread in the Off Topic subforum.

I haven't actually used AbiWord, but I am very pleased with OOo 2.0. I did try out OOo version 1, but I wasn't too impressed, and if you only have version 1, you should definitely upgrade. Otherwise, I respect your decision, as a side-by-side comparison is better than the speculation on my part.

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Post by SSCBen » Sun May 14, 2006 9:50 pm

This thread only exists to discuss the article and offer suggestions and improvements for the posted segments. The final article will only be featured on the website. ;)

I've just updated my OpenOffice build to 2.0 right now, so I'll take a look at what's new. Looks about the same from my first impression, but we'll see.

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