Numerical Modeling Of Particle Deposition In Turbine Cascade

Impurities ingested in the fuel and air may deposit on the surface of turbine components during the operation of aero engines. The presence of such deposits will change the roughness of the blade surface and even seriously affect the aerodynamic performance of each turbine component and the overall safety of the engine. In this study, a new deposition prediction model was developed, which utilizes the User Defined Function (UDF) of Fluent and mesh reconstruction technique to simulate the long-term accumulation of deposition on a nozzle guide vane. Based on the critical viscosity model and the critical velocity model, considering the elasticity and viscosity of particles, some improvements to the model were proposed. The shear removal of individual particles and bulk deposits have been considered in the new deposition model. The simulation result of deposition distribution was verified by comparing with the experimental results obtained under the low temperature wax deposition. Its consistency and problems were also discussed. Subsequently, the increase of deposition thickness with time was shown. The effects of the detachment model and free flow temperature on the deposition distribution were studied. The results show that the deposition at the leading edge of turbine vanes increases fastest with time. The deposition distribution may be more accurate if the detachment model is taken into account. The amount of deposition on the vane pressure surface and stagnation line will increase with the increase of free flow temperature.