is there a .......?

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andicirk
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is there a .......?

Post by andicirk »

just a quick question is there a simulator or a table that will give me the a conversion from lets say a water rocket energy source ( 2lires of air +300ml of water x10bar = class (?) rocket motor ,i ask this as im looking at a rocket building simulator that is only for motor rockets and so i can roughly add the correct engine power...( iam fuuly aware that this will not give optimum results as the wrocket if i use the example above will become 300grams lighter within seconds of the launch.

this is more just an exercise to try and combine multiple simulators to create the optimum wrocket based on the class c rules


thanks in advance
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rockets-in-brighton
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Re: is there a .......?

Post by rockets-in-brighton »

andicirk wrote:just a quick question is there a simulator or a table that will give me the a conversion from lets say a water rocket energy source ( 2lires of air +300ml of water x10bar = class (?) rocket motor ,i ask this as im looking at a rocket building simulator that is only for motor rockets and so i can roughly add the correct engine power...( iam fuuly aware that this will not give optimum results as the wrocket if i use the example above will become 300grams lighter within seconds of the launch.

this is more just an exercise to try and combine multiple simulators to create the optimum wrocket based on the class c rules


thanks in advance

This article (PDF) http://www.apogeerockets.com/Education/ ... ter219.pdf describes how to use RockSim for Water Rocket simulations. The jist of the article is that you use Clifford Heath's sim to generate a thrust curve, and use a utiliity called TCTracer ("Thrust Curve Tracer", freeware, available here: http://www.thrustcurve.org/tctracer.shtml) to create an engine file which can be imported into RockSim. However, as one of the outputs of TCTracer is the pyro engine equivalent, for your purposes you can stop there.

Also, quite a few other sims give the thrust in Newton Seconds, which you can look up here http://en.wikipedia.org/wiki/Model_rock ... sification.

I believe I also have one sim installed on another machine, that actually gives the pyro equivalent, I'll check the name and post it later.

Hope this helps.
Cheers
Steve
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rockets-in-brighton
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Re: is there a .......?

Post by rockets-in-brighton »

rockets-in-brighton wrote:
I believe I also have one sim installed on another machine, that actually gives the pyro equivalent, I'll check the name and post it later.
Of course, it is the Paul Grosse sim, here http://ourworld.compuserve.com/homepage ... 2orckt.htm.
Cheers
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Re: is there a .......?

Post by Cloud Dancers »

rockets-in-brighton wrote:
rockets-in-brighton wrote:
I believe I also have one sim installed on another machine, that actually gives the pyro equivalent, I'll check the name and post it later.
Of course, it is the Paul Grosse sim, here http://ourworld.compuserve.com/homepage ... 2orckt.htm.
That is a great simulator. Just make sure that you run it on an older PC (like win98 if you want the graphing functions to work). If you install it on a newer OS that is NT based like xp it will crash if you try to see the 3D graphs. All of the other functions and calculations will work though.
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andicirk
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Re: is there a .......?

Post by andicirk »

thanks everyone for the quick replies

i wonder if between us we can create a simulator topic in the links section that way without having to hunt through the entire internet ppl would have fast access to as many tools as possible ......


maybe we could split it into sections ... freeware ,shareware and comercial

if you read this admin is it possible to create a section like this?


thanks
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Re: is there a .......?

Post by WRA2 »

andicirk wrote:thanks everyone for the quick replies

i wonder if between us we can create a simulator topic in the links section that way without having to hunt through the entire internet ppl would have fast access to as many tools as possible ......


maybe we could split it into sections ... freeware ,shareware and comercial

if you read this admin is it possible to create a section like this?


thanks
We could create a sticky topic in the "links" section for "Simulators" and then everyone could add their favorite one to the list. once the list was populated I could then add to the links page on the main WRA2 site and organize them as "free", "commercial", and "home brew" .

We already have some on the "links" page.

http://www.wra2.org/WRA2_Links_Page.php

If we get enough we could even make a dedicated page for them. :WRA2:
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andicirk
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Re: is there a .......?

Post by andicirk »

brilliant thanks alot
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Re: is there a .......?

Post by WRA2 »

I created a sticky thread for simulators in the "links" forum. Thanks for the suggestion.
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The Sky Dart
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Re: is there a .......?

Post by The Sky Dart »

rockets-in-brighton wrote:This article (PDF) http://www.apogeerockets.com/Education/ ... ter219.pdf describes how to use RockSim for Water Rocket simulations. The jist of the article is that you use Clifford Heath's sim to generate a thrust curve, and use a utiliity called TCTracer ("Thrust Curve Tracer", freeware, available here: http://www.thrustcurve.org/tctracer.shtml) to create an engine file which can be imported into RockSim. However, as one of the outputs of TCTracer is the pyro engine equivalent, for your purposes you can stop there.

Also, quite a few other sims give the thrust in Newton Seconds, which you can look up here http://en.wikipedia.org/wiki/Model_rock ... sification.

I believe I also have one sim installed on another machine, that actually gives the pyro equivalent, I'll check the name and post it later.

Hope this helps.
Interesting. I independently came to the same idea of combining RockSim and a trust curve obtained from elsewhere. To be honest I wouldn't trust the Clifford Heath's sim. I prefer this one: http://www.et.byu.edu/~wheeler/benchtop/sim.php. Results of calculations were verified by measurements which is very important in my opinion. Comparing to it the Clifford Heath's sim produces more optimistic results. I wonder if anyone has ever compared it to the real life data.
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rockets-in-brighton
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Re: is there a .......?

Post by rockets-in-brighton »

The Sky Dart wrote: Interesting. I independently came to the same idea of combining RockSim and a trust curve obtained from elsewhere. To be honest I wouldn't trust the Clifford Heath's sim. I prefer this one: http://www.et.byu.edu/~wheeler/benchtop/sim.php. Results of calculations were verified by measurements which is very important in my opinion. Comparing to it the Clifford Heath's sim produces more optimistic results. I wonder if anyone has ever compared it to the real life data.
Clifford Heath's sim saw a lot of use by the water rocket community back in the late 90s, especially for determining Cd from test flights. apparently with useful results. He still hangs out on The Other Forum, you could always ask him how he validated it.
Cheers
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Re: is there a .......?

Post by U.S. Water Rockets1 »

rockets-in-brighton wrote:
The Sky Dart wrote: Interesting. I independently came to the same idea of combining RockSim and a trust curve obtained from elsewhere. To be honest I wouldn't trust the Clifford Heath's sim. I prefer this one: http://www.et.byu.edu/~wheeler/benchtop/sim.php. Results of calculations were verified by measurements which is very important in my opinion. Comparing to it the Clifford Heath's sim produces more optimistic results. I wonder if anyone has ever compared it to the real life data.
Clifford Heath's sim saw a lot of use by the water rocket community back in the late 90s, especially for determining Cd from test flights. apparently with useful results. He still hangs out on The Other Forum, you could always ask him how he validated it.
Someone should tell those guys about this forum, so we have everyone in the hobby together in one place.
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