Research On Temperature Addition Of Aeroengine Oil System

Work reliability of aeroengine is largely influenced by oil system.Temperature of transition chamber becomes higher and higher due to the promotion of performance of engine.Weak link of lubrication and cooling can be found by evaluating temperature addition,based on which some improvement can be made.Some parametres are calculated in this paper such as heat generation and force of accessory transmission components,heat dissipation of chamber,temperature addition of oil with the combination of power loss model,fluid gravity film assumption and fluid network theory.Rotational speed is calculated by transmission ratio.Transfer power is accumulated reversely,which are the middle parametres of calculating force.Force parameters are calculated by mechanics analysis model within two kinds of coordinate systems,which is the need of calculating heat generation.Heat generation is calculated by power loss model.Heat dissipation is calculated by heat convection theory.Oil flow rate is calculated by fluid network theory,which is the need of evaluating temperature addition.Temperature addition calculation is completed based on three parameters.Comprehensive calculation software of oil system is developed according to parameters calculation method,including force,heat generation,heat dissipation and temperature addition.Some parameters of oil in turbine propeller engine,like speed,force,heat generation and heat dissipation,temperature addition are calculated by this tool.Force results of bearings calculated by software are consistent with measuring results.Some conclusions are obtained by analyzing calculation results.First of all,the way oblique transmission of power extraction is inefficient,which need to be improved.Secondly,heat of bearings is larger than that of gears in transmission chamber,which need better lubrication and cooling,like using ceramic base bearing and increasing number of nozzle.Thirdly,heat generation of chamber contained components with high speed and large force is severe,lubrication method of which need to be improved.Safety margin of chamber 4 is rather small,whose lubrication way need to be improved,like using jet lubrication instead of grease.Oil with high temperature after cooling flows into return line for safety.Changing rule of temperature addition is nonlinear and better cooling performance of oil can be achieved by reasonable flow rate.Accuracy of temperation addition evaluation is improved by adding heat dissipation correction.Last but not least,performance of lubrication and cooling is improved while chamber's heat dissipation performance is decreased simultaneously by the increase of oil's flow rate.