Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian regions.However,their acoustic performances are constrained by the vibration result...Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian regions.However,their acoustic performances are constrained by the vibration resulting from the unavoidable ocean current in some degree.The influence of such vibrations is quantitatively analyzed by means of modeling the simplified models of two deployment configurations involving the positive buoyant buoy and neutral buoy system.The corresponding formulas are deduced respectively for the deployment configuration buoy systems in the motion state firstly.Then the simulation software is developed and some numerical simulations are put up via the Runge-Kutta method.The simulation results and theoretical analysis indicate that the neutral buoy will be an excellent design protocol in engineering application in comparison with the positive buoyant buoy.展开更多
In this paper,several exact expressions for the mean heat flux at the wall(qw)for the compressible turbulent channel flows are derived by using the internal energy equation or the total energy equation.Two different r...In this paper,several exact expressions for the mean heat flux at the wall(qw)for the compressible turbulent channel flows are derived by using the internal energy equation or the total energy equation.Two different routes,including the FIK method and the RD method,can be applied.The direct numerical simulation data of compressible channel flows at different Reynolds and Mach numbers verify the correctness of the derived formulas.Discussions related to the different energy equations,and different routes are carried out,and we may arrive at the conclusion that most of the formulas derived in the present work are just mathematical ones and that they generally are lacking in clear physical interpretation in our opinion.They can be used to estimate qw,but might not be suitable for exploring the underlying physics.展开更多
文摘Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian regions.However,their acoustic performances are constrained by the vibration resulting from the unavoidable ocean current in some degree.The influence of such vibrations is quantitatively analyzed by means of modeling the simplified models of two deployment configurations involving the positive buoyant buoy and neutral buoy system.The corresponding formulas are deduced respectively for the deployment configuration buoy systems in the motion state firstly.Then the simulation software is developed and some numerical simulations are put up via the Runge-Kutta method.The simulation results and theoretical analysis indicate that the neutral buoy will be an excellent design protocol in engineering application in comparison with the positive buoyant buoy.
基金the National Natural Science Foundation of China(Grant Nos.11822208,11772297,and 91852205)Guangdong provincial Key Laboratory(Grant No.2019B20203001).
文摘In this paper,several exact expressions for the mean heat flux at the wall(qw)for the compressible turbulent channel flows are derived by using the internal energy equation or the total energy equation.Two different routes,including the FIK method and the RD method,can be applied.The direct numerical simulation data of compressible channel flows at different Reynolds and Mach numbers verify the correctness of the derived formulas.Discussions related to the different energy equations,and different routes are carried out,and we may arrive at the conclusion that most of the formulas derived in the present work are just mathematical ones and that they generally are lacking in clear physical interpretation in our opinion.They can be used to estimate qw,but might not be suitable for exploring the underlying physics.
