Factors affecting leak rate

1) The influence of ambient temperature

     The thermal expansion and contraction of the material will cause the change of the geometric size of the leak; the change of the gas temperature will cause the change of the gas density and viscosity coefficient, which will lead to the change of the gas flow rate.

2) The influence of the pressure difference at both ends of the leak

     If the air pressure at both ends of the leak is equal and the composition is the same, that is, when the pressure difference is zero, there is no gas flow in the leak from the macroscopic view, and it is actually in a dynamic equilibrium state; when there is a pressure difference between the two ends of the leak, the leak There will be airflow from the high-pressure end to the low-pressure end. The greater the pressure difference, the greater the flow rate. When the leak hole is a convergent type, if it leaks into the atmosphere, the Mach number Ma ≤ 1, that is, it will not exceed the speed of sound, and the leak rate tends to be saturated.

3) Influence of gas quality

     The greater the mass, the more difficult it is to pass through the leak.

4) The effect of leak expansion

     Due to the effect of pressurization, microcracks will develop, leading to increased leakage.

     Therefore, the temperature, pressure, gas type and other conditions should be stated when giving the leak rate value.

(huiputech)