Recent content by chyvak

Thank you very much. I believe I have the full picture now.

This was a bit imprecise. I am well aware that external fluid flow around a rocket and internal fluid flow in a rocket are very different and have different origins. What I mean to say here is that from a system analysis perspective they are just stresses on the system boundary.

But is buoyancy really something extra that needs to be included in addition to the integral of the pressure/shear over the entire system boundary? I don’t believe so. If we were able to integrate the stress tensor (pressure and shear) over the entire system boundary then I don’t see what other...

Thank you for your detailed reply. It was exactly what I was hoping for. No, I am not trying to classify this term as either a thrust term or a drag term, merely to understand where it is coming from. In analyzing the forces acting on the system I could identify the above mentioned integral...

That is exactly my point. The correct term to include in the equation of motion is the integral of the pressure and shear stresses over the system boundary. Since this is indeed very complicated when the engine is operating, that integral is replaced by the integral over an unpowered system...

My first post, and a very long one... I have problems understanding the prolific use of a certain term in the rocket thrust equation and its validity. The general rocket thrust equation contains a term referred to as the pressure thrust. It is calculated as (p_e – p_a)Ae where p_e is the...