The flight of a water rocket involves complicated flows such as a gas–liquid two-phase flow in a pressure tank and a jet flow in an ejection hole. It can be applied to various phenomena by developing a method of reproducing and analyzing complicated phenomena. We simulated the flight of a calculation model of a water rocket by computational fluid dynamics. We conducted the simulation to estimate the thrust data of the calculation model and fluid–structure interaction. The simulated flight trajectory qualitatively matched that obtained from a previous experiment. In addition, it was possible to confirm changes in the attitude of the water rocket and vortices generated around it by simulating the pressure distribution on the surface of it and the flow around it. Therefore, it was possible to simulate the flow around a flying water rocket, which cannot be obtained through conventional theoretical calculations and experiments.

水火箭的飞行涉及复杂的流动，例如压力罐中的气液两相流和喷射孔中的射流。通过开发一种再现和分析复杂现象的方法，它可以应用于各种现象。我们通过计算流体动力学模拟了一个水火箭计算模型的飞行。我们进行了模拟以估计计算模型的推力数据和流固耦合。模拟的飞行轨迹在质量上与从先前实验中获得的轨迹相匹配。此外，通过模拟其表面的压力分布和周围的流动，可以确认水火箭的姿态变化和周围产生的涡流。因此，可以模拟飞水火箭周围的流动，