Air Flow Simulation

I'm trying to write a piece of code that calculates the flow of air through a very long, narrow tube. The specific application is to simulate the action of brakes on a train, but I don't believe you need to know anything about trains or railroads to make these calculations. I can provide all of the general information about brake behavior, particular rates of air flow, etc... My problem in particular is trying to figure out how to calculate in a linear program things that are really going on simultaneously. For instance, it is theoretically possible in such a long tube that one end could be increasing air pressure while the other end is decreasing because of actions already taken several seconds beforehand. I have a C#.NET application that you can use as a starting point, or you may just want to start from scratch since my code doesn't really work very well. **Clarification:** This project needs to be a simulator, meaning that the calculations are triggered by a public function call that passes some unknown elapsed time (measured in seconds with a value >= 0.0 and < 1.0) since the last calculation. Deliverables must include full source code that I can review and integrate into a larger piece of software that I am writing. The purpose of the requested Windows Forms project deliverable is to see the numbers being crunched and verify proper functionality before integrating into my main project, whose only output is 3D animation. This is a personal project, not funded by any company or corporation. As a programmer myself, I can tell you my budget is WAY under what this software is worth. I guess I'm looking for someone who enjoys the challenge more than getting paid. ## Deliverables See attached. Word document with specifications and my original source code (VS2008, C#.NET) are included. My project source is included for your reference. I do not require that you use it if you feel a clean start would be better. I will accept help in the form of either a collaborative effort or independent development based solely on the attached project spec.