V锥流量计火箭发动机液氢液氧推进剂测量性能

To investigate the new measurement method of the cryogenic propellant flow rate of the rocket engine, e.g., the flow rate of the liquid hydrogen (LH₂) and the liquid oxygen (LO₂), the performance of the V-cone flowmeter when measuring the cryogenic fluid was investigated by numerical simulation. The Realizable κ-ε model was used to describe the turbulence. The Schnerr-Sauer cavitation model was used to investigate the effects of cavitation on the performance of the V-cone flowmeter. A UDF was also added to take into account the effects of latent heat of vaporization. The discharge coefficient and pressure loss coefficient of the V-cone flowmeter were discussed when the fluids were cryogenic fluids and water. The measurement error of the flowmeter was also analysed. The results show that the discharge coefficient and pressure loss coefficient are almost constant when the Reynolds number in a 'stable region', where the average discharge coefficient of both the cryogenic fluids and the water around the room temperature is essentially equal. It is also found that the lower limits of the Reynolds number for the constant discharge coefficient is very close for each fluid, while the upper limits of Reynolds number are quite different. The cryogenic fluids, especially LH₂, have wider stable Reynolds number ranges than the water. In addition, there is little effect of cavitation on the discharge coefficient and pressure loss coefficient at the initial stage of cavitation. When the cavitation occurred downstream of V-cone affects the pressure around the low pressure tapping, the discharge coefficient decreases rapidly with Reynolds number increasing, while the pressure loss coefficient rises quickly. Under the Reynolds number range of the 'stable region', the V-cone flowmeter can accurately predict the flow rate of LH₂, LO₂ and water, whose relative errors are with ±0.5%. The measurement of LH₂ and LO₂, in particular, has high accuracy over a wide range of Reynolds number. The results also demonstrate that the effects of cavitation on the measurement error of the flow rate are small. This study opens a new avenue for measuring the cryogenic propellant flow rate of the liquid rocket engine.