项目来源

俄罗斯科学基金(RSF)

项目主持人

Чувахов Павел Владимирович,Доктор физико-математических наук

项目受资助机构

федеральное государственное автономное образовательное учреждение высшего образования"Московский физико-технический институт",г Москва

项目编号

19-79-10132

财政年度

2022,2019

立项时间

未公开

项目级别

国家级

研究期限

未知 / 未知

受资助金额

未知

学科

ENGINEERING SCIENCES-Motion of objects and apparatuses within different media

学科代码

09-09-104

基金类别

未公开

восприимчивость ; ламинарно-турбулентный переход ; сверхзвуковой полёт ; крыло ; физически обоснованное моделирование ; прямое численное моделирование ; теория устойчивости ; receptivity ; laminar-turbulent transition ; supersonic flight ; wing ; physics-based modelling ; direct numerical simulation ; stability theory

参与者

未公开

参与机构

未公开

项目标书摘要：nnotation:Occurrence of turbulence is one of the key problems of fundamental fluid dynamics and applied aerodynamics of flight vehicles(FV)of new generation,including highly energy-conserving and ecological airplanes with natural and/or artificial laminarization,and supersonic airplanes with low sonic boom level.In spite of many years effort of scientific laboratories over the world,physical mechanisms behind the occurrence of turbulence in supersonic boundary layers are poorly studied.So far,there are no reliable methods to predict location of laminar-turbulent transition(LTT)regions as well as to compute coefficients of viscous friction and heat flux in such regions for elements of real supersonic FV.This,in turn,complicate the development of efficient laminarization systems.Urgency and relevance of the Project is connected to the need for ecological and highly energy-conserving transportation systems.External disturbances triggering the process of laminar-turbulent transition cannot be modeled in wind tunnels.Flight experiments are expensive and yield little information.Therefore,numerical simulations become more valuable for the problem in hand.The main tool to solve the tasks of the Project will be the method of direct numerical simulation(DNS)based on the solution of three-dimensional unsteady Navier-Stokes equations for a perfect gas.Simulation results will be compared with theoretical,numerical and wind tunnel data available.Focused on supersonic flow over an upswept wing with thin airfoil,linear stability computations will be performed and frequency-wave number range of unstable disturbances will be determined along with the most‘dangerous’type of disturbances.Vortical disturbances of inertial or Kolmogorov’s intervals of atmospheric turbulence are supposed to play the most important role in LTT process.Their spectrum is of simple shape.This lets us model the external LTT-triggering disturbances with relatively simplisity under the conditions of supersonic flight.Testing of this hypothesis is one of the main objectives of the Project.A series of DNS computations will help in determination to what extent the process of LTT depends on the parameters of atmospheric turbulence.All stages of LTT will be investigated,including nonlinear mechanisms of occurrence of turbulent spots.The dependence of such mechanisms on the external disturbance environment will also be determined.The preset Project will allow to answer the following questions of principal importance.Which mechanism of nonlinear breakdown leading to formation of turbulent spots dominates on the upswept wing with thin airfoil under the typical conditions of supersonic flight?To what extent does it depend on atmospheric disturbances?Which way should one model(or predict)this dependence for natural conditions in order to provide acceptable accuracy of computations of aerodynamic and heat characteristics of the wing under transitional flow regime?The formulated problems of the Project are novel or poorly studied both in Russia and abroad.Professionals with many years of experience in this scope of science are to solve them.The results of the Project are expected to correspond to the worldwide level and even exceed it.Expected results:The Project will help to obtain reliable physics-based results on laminar-turbulent transition(LTT)at supersonic speeds of flight.This is one of the key problems of fundamental fluid dynamics and applied aerodynamics of flight vehicles(FV)of new generation,including highly energy-conserving and ecological airplanes with natural and/or artificial laminarization,and supersonic airplanes with low sonic boom level.Algorithms and tools for application of the planned results will be developed.Focused on supersonic flow over an upswept wing with thin airfoil,a frequency-wave number range of unstable disturbances will be determined along with the most‘dangerous’type of disturbances.Our preliminary estimations have shown that vortical disturbances of inertial or Kolmogorov’s intervals of atmospheric turbulence are supposed to play the most important role in LTT process.If this is the case,the disturbance spectrum is of simple shape that depends only on two parameters:dissipation rate of turbulent energy and kinematic viscosity.As a result,this lets us model the external LTT-triggering disturbances with relatively simplicity under the conditions of supersonic flight.Such models will be developed and used to formulate boundary conditions for direct numerical simulation(DNS)of laminar-turbulent transition,including excitation,development and nonlinear breakdown of unstable disturbances up to occurrence of turbulent spots.A series of DNS computations with different values of dissipation rate of turbulent energy(inherent to calm,moderate and strong atmospheric turbulence)will allow to understand for the first time to what extent the laminar-turbulent transition depends on the weather conditions as well as the way to predict this dependence during the design of supersonic wing.All stages of LTT will be investigated,physical mechanisms of occurrence of turbulence will be determined.As consequence,this enables to increase the accuracy of computations of viscous friction and heat flux,to develop new laminarization systems and to reliably assess their efficiency.This confirms that the planned results are urgent and can be applied to economics and social issues.The formulated problems of the Project are novel or poorly studied both in Russia and abroad.Professionals with many years of experience in this scope of science are to solve them.The results of the Project are expected to correspond to the worldwide level and even exceed it.

Application Abstract: Annotation:Occurrence of turbulence is one of the key problems of fundamental fluid dynamics and applied aerodynamics of flight vehicles(FV)of new generation,including highly energy-conserving and ecological airplanes with natural and/or artificial laminarization,and supersonic airplanes with low sonic boom level.In spite of many years effort of scientific laboratories over the world,physical mechanisms behind the occurrence of turbulence in supersonic boundary layers are poorly studied.So far,there are no reliable methods to predict location of laminar-turbulent transition(LTT)regions as well as to compute coefficients of viscous friction and heat flux in such regions for elements of real supersonic FV.This,in turn,complicate the development of efficient laminarization systems.Urgency and relevance of the Project is connected to the need for ecological and highly energy-conserving transportation systems.External disturbances triggering the process of laminar-turbulent transition cannot be modeled in wind tunnels.Flight experiments are expensive and yield little information.Therefore,numerical simulations become more valuable for the problem in hand.The main tool to solve the tasks of the Project will be the method of direct numerical simulation(DNS)based on the solution of three-dimensional unsteady Navier-Stokes equations for a perfect gas.Simulation results will be compared with theoretical,numerical and wind tunnel data available.Focused on supersonic flow over an upswept wing with thin airfoil,linear stability computations will be performed and frequency-wave number range of unstable disturbances will be determined along with the most‘dangerous’type of disturbances.Vortical disturbances of inertial or Kolmogorov’s intervals of atmospheric turbulence are supposed to play the most important role in LTT process.Their spectrum is of simple shape.This lets us model the external LTT-triggering disturbances with relatively simplisity under the conditions of supersonic flight.Testing of this hypothesis is one of the main objectives of the Project.A series of DNS computations will help in determination to what extent the process of LTT depends on the parameters of atmospheric turbulence.All stages of LTT will be investigated,including nonlinear mechanisms of occurrence of turbulent spots.The dependence of such mechanisms on the external disturbance environment will also be determined.The preset Project will allow to answer the following questions of principal importance.Which mechanism of nonlinear breakdown leading to formation of turbulent spots dominates on the upswept wing with thin airfoil under the typical conditions of supersonic flight?To what extent does it depend on atmospheric disturbances?Which way should one model(or predict)this dependence for natural conditions in order to provide acceptable accuracy of computations of aerodynamic and heat characteristics of the wing under transitional flow regime?The formulated problems of the Project are novel or poorly studied both in Russia and abroad.Professionals with many years of experience in this scope of science are to solve them.The results of the Project are expected to correspond to the worldwide level and even exceed it.Expected results:The Project will help to obtain reliable physics-based results on laminar-turbulent transition(LTT)at supersonic speeds of flight.This is one of the key problems of fundamental fluid dynamics and applied aerodynamics of flight vehicles(FV)of new generation,including highly energy-conserving and ecological airplanes with natural and/or artificial laminarization,and supersonic airplanes with low sonic boom level.Algorithms and tools for application of the planned results will be developed.Focused on supersonic flow over an upswept wing with thin airfoil,a frequency-wave number range of unstable disturbances will be determined along with the most‘dangerous’type of disturbances.Our preliminary estimations have shown that vortical disturbances of inertial or Kolmogorov’s intervals of atmospheric turbulence are supposed to play the most important role in LTT process.If this is the case,the disturbance spectrum is of simple shape that depends only on two parameters:dissipation rate of turbulent energy and kinematic viscosity.As a result,this lets us model the external LTT-triggering disturbances with relatively simplicity under the conditions of supersonic flight.Such models will be developed and used to formulate boundary conditions for direct numerical simulation(DNS)of laminar-turbulent transition,including excitation,development and nonlinear breakdown of unstable disturbances up to occurrence of turbulent spots.A series of DNS computations with different values of dissipation rate of turbulent energy(inherent to calm,moderate and strong atmospheric turbulence)will allow to understand for the first time to what extent the laminar-turbulent transition depends on the weather conditions as well as the way to predict this dependence during the design of supersonic wing.All stages of LTT will be investigated,physical mechanisms of occurrence of turbulence will be determined.As consequence,this enables to increase the accuracy of computations of viscous friction and heat flux,to develop new laminarization systems and to reliably assess their efficiency.This confirms that the planned results are urgent and can be applied to economics and social issues.The formulated problems of the Project are novel or poorly studied both in Russia and abroad.Professionals with many years of experience in this scope of science are to solve them.The results of the Project are expected to correspond to the worldwide level and even exceed it.