Strength of wheels of high-pressure hydrogen pumps

With the example of an oxygen-hydrogen liquid-propellant rocket engine with afterburing for the launch vehicle "Energiya", we consider the structural strength of impellers of a hydrogen pump. It is shown that the specific strength of the structural materials of impellers in liquid hydrogen is considerably influenced by their plasticity. On the basis of the data of experiments, the admissible peripheral speeds are recommended for impellers made of cast steels and titanium alloys. The method of hot isostatic pressing for producing the impellers of Ti alloys provides a number of advantages over other techniques. This method makes it possible to ensure an admissible peripheral speed of impellers up to 630 m/sec in the nominal mode and 690 m/sec for short periods in the maximum operational modes of the liquid-propellant rocket engine. Materials used: VT5-1kt, VT6S titanium base alloys, AK6 aluminum base alloy, VNL-1, VNL-6 steels, and EP915 nickel alloy.