Study On Flow And Heat Transfer Characteristics Of Non-Isothermal Closed Rotor-Stator Disk Cavity

Among the numerous structural parts of aviation engines,the turbine disc is the main key part and life-limiting part,and it bears its own centrifugal load,external load of the wheel disc and extremely high thermal load at the same time.At present,increasing the temperature before the turbine is one of the main ways to improve the comprehensive performance of aviation engines.The increase in temperature will further increase the thermal stress level of the wheel due to the heat load,resulting in a decrease in the life of the wheel.Therefore,it is necessary to carry out in-depth research on the flow and heat transfer inside the turbine disk cavity,so as to provide a reliable method for accurately estimating the temperature of the turbine disk and proposing a cooling scheme for the disk.In this paper,the classic closed rotor-stator disk cavity is taken as the research object,and the combination of theoretical analysis and constant numerical simulation is used to explore the three different working conditions of axial,radial,and axial and radial temperature differences.The influence of the thermal Rossby number on the flow and heat transfer characteristics of the disc cavity,including the dimensionless velocity distribution of the disc cavity and the core area of the disc cavity,the temperature distribution in the disc cavity,and the Nusselt number distribution of the four walls,and the The mechanism of its influence has been deeply analyzed.The RANS method was used for constant numerical simulation,and the grid independence verification was completed.According to the numerical method verification of experimental data in relevant literature,the calculation results are consistent with the experimental data,which provides a reliable basis for the subsequent numerical calculations in this paper.The flow and heat transfer characteristics of a closed rotor-stator system with temperature difference in the axial direction are explored.When there is an axial temperature difference,the basic flow structure of the disk cavity is consistent with the isothermal closed cavity,which is composed of the boundary layer of the rotating disk surface and the rotating core in the middle,and the rotation ratio of the core area remains unchanged along the axial direction.For the same thermal Rossby number,the local Nusselt number of the static disk increases with the increase of the radius;for different thermal Rossby number,at the same radius position,as the thermal Rossby number increases,the The velocity gradient of the fluid in the boundary layer decreases,and the Nusselt number decreases.The flow and heat transfer characteristics of a closed rotor-stator disk cavity with radial temperature difference are explored.When there is a radial temperature difference,the basic flow of the disk cavity is consistent with the isothermal closed cavity,which is a typical Batchelor flow pattern.For the same thermal Rossby number,the temperature in the fluid core area remains constant along the radial direction,the local Nusselt number of the disk cover gradually increases along the axial direction,and the local Nusselt number of the disk center axis gradually decreases along the axial direction;For different thermal Rossby number and the same axial position,as the thermal Rossby number increases,the local Nusselt number of the disk cover increases,while the local Nusselt number of the disc axis decreases.A closed rotor-stator disk cavity with axial and radial temperature differences is explored.The flow in the disk cavity belongs to a typical Batchelor flow pattern(the flow is divided into two boundary layers separated by the middle rotating core).For the same thermal Rossby number,the temperature of the fluid core remains constant along the axial direction and decreases gradually along the radial direction.For different thermal Rossby number,as the thermal Rossby number increases,the local Nusselt number of the rotor-stationary disk decreases at the same radius position.Through the research on the flow and heat transfer characteristics of the non-isothermal closed rotor-stator disc cavity,it provides an effective basis for the accurate prediction of the turbine disc temperature,and provides a reliable method for the cooling scheme of the disc...