Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 03, 2023 - September 06, 2023
Nitrous oxide is an attractive option as an oxidizer for rockets because of its self-pressurized supply and safety. On the other hand, it is very close to the critical point at room temperature, so the prediction of its state quantity requires very complicated calculations. Prediction of the oxidizer flow rate is important for hybrid rockets, and various prediction equations have been proposed. In particular, the Homogeneous Non-Equilibrium Flow Model, which assumes that the mass flow rate of nitrous oxide takes a value between liquid single-phase flow and gas-liquid two-phase flow, is considered to be accurate. However, this HNE flow model does not consider the effect of injector geometry, and the authors proposed a new model, HNEIS, which considers injector geometry. From flow rate tests using several injectors with different geometries, it was found that the flow rate varies depending on the injector geometry even when the supply pressure is equal. It was also clear that the HNEIS could express this trend, whereas the HNE could not. On the other hand, there is a dissociation between the actual flow rate and the predicted flow rate by HNEIS, and the model needs to be improved.
