Interactions of vortices, thermal effects and cavitation in liquid hydrogen cavitating flows

The cavitating flow of liquid hydrogen over an ogive is numerically investigated in a compressible mathematic framework for both gas and liquid phase, based on the homogeneous mixture model coupled with Schnerr–Sauer cavitation model and large eddy simulation. The model for simulating the complex flow is firstly validated by comparing the calculations with the experiments by Hord. Then, the calculated unsteady evolutions of vapor content, temperature and pressure field within the cavity are presented. A special cavitation shedding mechanism, named the partially shedding mode, is revealed for the first time, in which, the primary cavity keeps quasi-steady, while, the much smaller cavity cloud is found to intermittently form near the leading edge inside the primary cavity, then convects downstream along the wall surface and flow out of the closure with a frequency of about 2500 Hz. As the separation of the small cloud from the primary cavity, the volume of the latter diminishes until it is totally swept away with a frequency of about 275 Hz, forming the so called cavitation cloud. The vorticity transport equation in a variable density flow is used to illustrate the complex phenomena of the partially shedding mode. The results reveal that the generation of vorticity mainly happens near the solid surface inside the cavity in non-isothermal cases while it mainly happens at the interface and closure part in isothermal cases. The dynamic interactions between vortices, cavitation and thermal effects are the fundamental cause of the generation of the small bubble clouds, and the three are indispensable. This research helps to understand the complex dynamic mechanism of the cavitation cloud in liquid hydrogen with strong thermal effects. •Cavitation dynamics of LH2 in fully compressible framework are modeled by LES.•Model is validated by available experimental results.•Partially shedding, apart from fully shedding mode, is firstly illustrated.•Interactions of vortices, thermal effects and cavitation are illuminated.