Investigation On Nozzle Trailing Edge Shock Modulation Method Of VNT

Turbocharger has been widely used, especially the VNT radial turbine, in theadvantages of reducing emissions of harmful gases and matching engine and attentionwithin the range of conditions. The research of the VNT radial turbine mainlyconcentrates in the mechanism of the internal flow guide vane blade tip clearanceleakage flow and the turbine performance; however, nobody has paid attention to theinvestigation on shock modulation method of VNT radial turbine. Therefore, theinvestigation on guide vane trailing edge shock weakening research of the VNT radialturbine has certain academic value and engineering application prospects. In thispaper, VNT trailing edge shock wave intensity modulation method has been studied,and put forward three kinds of guide vane type of shock wave modulation method,guide blade trailing edge tilts, the groove structure on the suction surface shock waveposition, change of the suction surface of blade thickness distribution, the mainresearch results are as follows:Turbine guide vane trailing edge slope is tilted, and the scope is reduced, nothigh throughout the entire leaf range; Shock wave intensity decreased obviously, theimpact on the downstream rotor blade leading edge is abate, distracted the impact, therotor blade tip region of the aerodynamic load decreases obviously, reduce thedownstream rotor blade before causes shock waves caused by pressure fluctuationamplitude.The groove structure on the suction side of the guide vane shock position,significantly reduces the guide vane trailing edge shock wave intensity, reduced theinfluence of shock wave. The groove structure in the0.5mm deep makes shock waveintensity reduce by about3.29%, the influence of shock wave reduce about10%,middle lobe rotor blades aerodynamic load to get high position decrease obviously,reduce the easy damage of turbine rotor blade leading edge between high position andhigh cycle fatigue fracture risk.Increasing the thickness of the suction side of the guide vane type method,results in guide vane trailing edge and the rotor blade leading edge distance reduce, air after formed stator blade row of pneumatic throat swelling degree aggravate,boosting the guide blade trailing edge shock waves; Reducing the suction side of theguide vane side blade trailing edge and the thickness of the type of repair method notonly can increase the stator blade rows between the formation of the pneumatic throatarea, reduce the degree of the expansion of the gases, reduce the guide vane exit Machnumber, and the guide vane trailing edge shock position is moved forward, increasingthe shock wave and the relative range of the turbine blade downstream make theshock wave intensity decrease significantly, reducing the downstream rotor blademiddle lobe induced by shock wave high position and high cycle fatigue fracture risk.