Calculation of the Adiabatic Flow Time of an Ideal Gas from a Constant Volume Reservoir, Accounting for the Process of Opening the Exhaust Valve

About the author:

Vadim V. Tarasov, Cand. Sci. (Tech.), Associate Professor, Department of Engineering Graphics, Bauman Moscow State Technical University; midav-5491@mail.ru

Abstract:

The author’s previous works have already considered the calculation of the process of adiabatic outflow of an ideal gas from a constant volume tank. It was assumed that the shut-off device (storage) at the outlet of the tank opens instantly and the area of the outlet during the expiration remains constant. This approach is possible when the start-up period (time to open the storage completely) is a small part of the total expiration time, for example, for large tanks or shut-off devices with rapid opening (safety valve). However, there may be cases where the start-up time will be commensurate with the total expiration time (control valve). In these cases, not accounting for the starting period can lead to a noticeable error in determining the total time of the flow.

In this paper, the author proposes a method that based on the accepted formulation of the problem, allows calculating the expiration time taking into account the change in the opening area of the valves. As an additional limitation for the calculation, it is assumed that the flow coefficient is a constant value equal to its time-averaged value.

References:

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