The function of the restrictor is to supply oil to the combustion chamber before the fuel-regulating valve is opened in the acceleration phase, which can smoothly ignite the engine. In the cruise state, the fuel is supplied to the engine together with the fuel regulating valve. The restrictor is a short tube orifice. It is generally considered that the flow rate is proportional to the square of the differential pressure, ie QâˆÎ”p. However, in the flow characteristic test of the restrictor, it is found that when the pressure difference is greater than a certain value, the flow rate It no longer increases as the pressure difference increases, but remains at a certain value. This study of this peculiar phenomenon shows that cavitation occurs in the flow restrictor when the pressure difference reaches a certain value. By analyzing the change process of the pump outlet pressure p and the fuel pressure p during the acceleration process, it can be determined that there is also a cavitation phenomenon in the flow restrictor during the start-up acceleration of the turbojet engine. The starting acceleration section of the turbojet engine is a weak link in the whole working process, and the cavitation phenomenon will have a certain influence on the starting acceleration process. This paper first analyzes the mechanism of cavitation generation, and then discusses the impact on the acceleration process of the engine based on the inherent characteristics of cavitation, and gives corresponding solutions. Mechanism analysis of cavitation. Physical process of cavitation When the liquid flows through the orifice, the static pressure drops to a minimum at the over-contraction section of the damper. When the pressure in the stream drops to the air separation pressure of the liquid, the gas is separated from the liquid. Come out, these bubbles gradually grow up with some small bubbles as the core. When the pressure in the liquid is further reduced to slightly below the saturated vapor pressure of the liquid, the liquid will rapidly vaporize and cavitation will occur. Conditions for cavitation A large number of experimental studies have shown that for a tube restrictor with a length to diameter ratio greater than 2, in order to operate in an airless state, a back pressure of 22% or more of the inlet pressure must be established at the outlet. That is, the pressure difference falling on the orifice should not exceed 0.78 p1. Therefore, the pressure at which the cavitation occurs before the orifice is judged. Titanium Dioxide R818,Rutile Titanium Dioxide R818,R-818 Titanium Dioxide Rutile,Rutile Titanium Dioxide Pigment R818 Wuxi Qijun New Material Co., LTD , https://www.qijuncoating.com