Similarity solution of subcritical pressure discharges from vessels for arbitrary gases

Measurement of the Reynolds Number Dependence of a Transient Air Jet from a Pressure Vessel

“…The pressure curve can be approximated within the first 14 s with a quadratic function 𝑝 1 (𝑡) = 2.6038𝑡 2 − 71.501𝑡 + 499.73, (5.5) which has a coefficient of determination of R 2 = 99.97 %. This is consistent with the model of Fischer et al (2022) . For a quantitative evaluation of the discharge durations 𝑡 𝑑𝑖𝑠 , the discharge duration 𝑡 𝑑𝑖𝑠 is defined according to Fischer et al ( 2022)…”

“…The experimental discharge duration of 𝑡 𝑑𝑖𝑠 = 13.66 s is about 10.8 % longer than the discharge duration of 𝑡 𝑑𝑖𝑠 = 12.32 s determined with the model of Fischer et al (2022). This could be related to the fact that the model of Fischer et al (2022) was designed for a thin-walled vessel, where pipe friction is not taken into account. Furthermore, the pressure profile shows very small error indicators.…”

“…The mean standard deviation of the pressure during the discharge drops from 𝜎(𝑝 1 (𝑡 = 0)) = 2.14 mbar at the beginning of the discharge to 𝜎(𝑝 1 (𝑡 𝑑𝑖𝑠 ) = 0.63 mbar at the end of the discharge. According to the model of Fischer et al (2022), the influence of the standard deviation of the pressure on the outflow velocity is thus ± 0.17 % at 𝑡 = 0 s and ± 6.11 % at 𝑡 = 𝑡 𝑑𝑖𝑠 . The error indicator for time results from the recording rate of 4.5 Hz, which corresponds to a measured value every 0.222 s. Since the error indicator for the pressure is similarly great, the variations in the temporal pressure curve could be attributed to the fact that the starting point of the outflow is within a time interval of 0.222 s and is thus not quite clearly defined.…”

“…The mean standard deviation of the internal vessel temperature at the beginning of the discharge is 𝜎(𝑇 1 (𝑡 = 0)) = 1.12 °C and 𝜎(𝑇 1 (𝑡 𝑑𝑖𝑠 )) = 1.00 °C at the end of the discharge. According to the model of Fischer et al (2022), the influence of the standard deviation of the internal vessel temperature on the outflow velocity is thus ± 0.19 % at 𝑡 = 0 s and ± 0.14 % at 𝑡 = 𝑡 𝑑𝑖𝑠 . Therefore, the influence of the temperature differences on the discharge velocity is negligible.…”