Search found 380 matches
- Sat Oct 24, 2015 1:15 pm
- Forum: Pneumatic Cannons
- Topic: Survey to help make better homemade water guns
- Replies: 0
- Views: 3717
Survey to help make better homemade water guns
https://docs.google.com/forms/d/1cd9N9VPBIBtLxRCRNrI1BYXyQaKlYbyiW5ZkRDAVtMw/viewform All, I haven't participated in this community for a while due to other time commitments. But I know there are a number of people who build water guns here, and I'm running a survey for one of my websites about what...
- Sat Mar 07, 2015 6:50 pm
- Forum: General How-To & Discussion
- Topic: Full Simulation of Gas Gun Systems
- Replies: 5
- Views: 4706
Re: Full Simulation of Gas Gun Systems
Nice work. What is GALE? I'm assuming it's a code you wrote, but I could be mistaken. How do the various codes compare against any measurements you've made? This sort of validation is really important if we want to understand how to make better launchers. I think if this comparison was done, you mig...
- Wed Feb 06, 2013 2:14 pm
- Forum: Pneumatic Cannons
- Topic: The supersonic ping pong gun
- Replies: 17
- Views: 5245
The professor replied back to my email: Ben, I have to admit that I have some of the same questions. We're in the process of doing a straight connector with no convergent section. I'm very eager to see what happens. Eventually, I'll need to do a CFD analysis as well. Mark So, it seems that we're on ...
- Wed Feb 06, 2013 8:57 am
- Forum: Pneumatic Cannons
- Topic: The supersonic ping pong gun
- Replies: 17
- Views: 5245
I emailed the professor. I'll post any response I get. My email is below. Hello Prof. French, I am a graduate student working in computational fluid dynamics who is also interested in the internal ballistics of compressed gas guns. I recently saw you and your students' supersonic ping-pong ball gun ...
- Tue Feb 05, 2013 10:14 pm
- Forum: Pneumatic Cannons
- Topic: The supersonic ping pong gun
- Replies: 17
- Views: 5245
I didn't watch the video before. I watched most of it now, and I only saw one test. If anyone could point out specifically where they did an otherwise equivalent test (e.g., with the vacuum) without the nozzle, I'd be interested in knowing. It's also worth noting that the professor in the video says...
- Mon Feb 04, 2013 9:53 pm
- Forum: Pneumatic Cannons
- Topic: The supersonic ping pong gun
- Replies: 17
- Views: 5245
As I said in the off-topic thread, I am skeptical the converging-diverging nozzle helped here. They didn't do a test without it best I can tell, so there's no solid way to know if it helped. These nozzles are mainly used when the inlet air is extremely hot to convert the heat into gas kinetic energy...
- Mon Feb 04, 2013 7:04 pm
- Forum: Off-Topic Hobbies
- Topic: "Offtopic-posts-topic" NSFW
- Replies: 6637
- Views: 1427985
- Wed Jan 23, 2013 8:23 pm
- Forum: General How-To & Discussion
- Topic: Spring Gun Design Tool Thread
- Replies: 15
- Views: 5418
Also what could be worth considering is forming a design programme that is made entirely from experimental data, have you ever considered such an idea yourself? It is certainly possible and attractive for the reasons you detail. However, it would be difficult even for simple low-speed pneumatics if...
- Tue Jan 22, 2013 9:18 pm
- Forum: General How-To & Discussion
- Topic: Spring Gun Design Tool Thread
- Replies: 15
- Views: 5418
Your graph, have you tested + recorded (or similar) where an actual pressure reading of the system would be taken at? I wonder how close it would lie to the two lines. Also your equation it's perplexing me what law/scientist/rule/parrot you got it from, I will definitely use it in future but I like...
- Tue Jan 22, 2013 7:55 am
- Forum: General How-To & Discussion
- Topic: Spring Gun Design Tool Thread
- Replies: 15
- Views: 5418
Split's right. Isothermal is demonstrably wrong even in simple cases. The higher the compression ratio, the worse the isothermal assumption is. Still, isothermal is okay if you are just getting started, but it should be corrected. I myself wrote an isothermal springer simulation back in late 2008, a...
- Thu Jan 17, 2013 10:01 am
- Forum: General How-To & Discussion
- Topic: Spring Gun Design Tool Thread
- Replies: 15
- Views: 5418
- Tue Sep 20, 2011 10:15 am
- Forum: Pneumatic Cannons
- Topic: Open source pneumatic gun simulation
- Replies: 18
- Views: 7026
I'm now in grad school. Long story, but I'm happy to be here. I decided to start working on the Lagrangian code again after I take the FE exam. As I recall, what I wrote before was unstable (probably due to typos, though it could be inherent to the approach) and as I haven't touched it since then, i...
- Sun Aug 14, 2011 11:35 am
- Forum: Pneumatic Cannons
- Topic: Open source pneumatic gun simulation
- Replies: 18
- Views: 7026
A status update: Things are proceeding slower due to a change of plans. When I last posted, I was thinking I'd have to get another job, but due to some connections at my old job, I should be able to start grad school this fall. Taking care of a bunch of paperwork and cleaning has occupied most of th...
- Sat Jul 30, 2011 8:57 am
- Forum: Pneumatic Cannons
- Topic: Open source pneumatic gun simulation
- Replies: 18
- Views: 7026
After a few days of thought, I've decided to reduce the number of goals for the first version. The first version will be written in Python. Why? Because I don't have to think about a lot of things I'll have to think about if I used a lower-level language. I already have too much on my plate. The fir...
- Mon Jul 25, 2011 9:34 pm
- Forum: Pneumatic Cannons
- Topic: Open source pneumatic gun simulation
- Replies: 18
- Views: 7026
Well, if you haven't written anything in Java then I guess I'll start in Python as I know it can handle what we need, I know it reasonably well, and it's not too hard to pick up if you know other languages. (This is "you" in a general sense.) It sounds like you might have used a time step that was t...