Hello ! I have a question to make, which really bothered me these days and i couldnt find a solution. I am currently studying the consequences of a gas flow ( methane, ethane in particular ) which is released from a hole ( in a pipe ) of a given diameter D , and from a given height H. The pressure of the gas is 50 Bara and the temperature of the pipe is 60 oC. My first problem is now, how can i decide about the shape that this gas release will take, its volume, its concentration ? In addition to that, if i have a large building in a quite short distance from the leak, and the gas cloud hits the building with high pressure ( and of course high velocity ) how can i decide what happens to the this cloud after that ? If the case is that it spreads out, what shapes will the "pieces" of the gas cloud take and how can i decide about their direction, volume,mass assuming that there is no wind ?

Thanks a lot in advance

>>My first problem is now, how can i decide about the >>shape that this gas release will take, its volume,
:> its concentration ?

Usually one performs different scenarios. Most important for getting permits is the worst case scenario. The answer to your question is just trial and error and alot of different scenarios.

>>In addition to that, if i have a large building in a >>quite short distance from the leak, and the gas cloud >>hits the building with high pressure ( and of course >>high velocity ) how can i decide what happens to the >>this cloud after that

Model it and see. Your concentration equation will tell you everything you need to know.

Note also that the most important thing here is the temperature and pressure profiles of the environment, and thus how your bouyant cloud reacts to it. There is nothing worse than a negatively buoyant cloud of pollution on a day with no wind >