Analytical study of volumetric scroll pump for liquid hydrogen circulating system

The paper presents analytical results of suction process of a volumetric scroll pump, which will be developed for circulating liquid hydrogen in a cold moderator system. The multi-block grid generation approach has been applied to generate a moving boundaries computational model. The finer mesh patterns have been generated in the near-wall regions. The Low-Reynolds number k-ε turbulence model has been solved for predicting Reynolds stresses and turbulent scalar fluxes. The analysis has been carried out under liquid hydrogen flow conditions. The heat transfer effect is neglected to simplify the study. The analytical results show that at the end of suction process the relative pressures increase significantly in a pocket while decrease continuously in another pocket. This phenomenon might damage scroll pump components if the high-pressure side is too high and/or the low-pressure side is too low until the cavitations occur. Therefore, the pocket should open to the discharge chamber before it closes and separates from the suction chamber in order to prevent the cavitations and extremely high-pressure regions. (author)