In this paper, some preliminary calculations and the experiments were performed to figure out the flow field, in which some rods were normally inserted into the main flow surrounded by a porous cavity. As a result, it...In this paper, some preliminary calculations and the experiments were performed to figure out the flow field, in which some rods were normally inserted into the main flow surrounded by a porous cavity. As a result, it is found that the starting shock wave severely interacts with the rods, the bow shock wave, its reflections, and the porous wall, which are numerically well predicted at some conditions. Moreover, inserting the rods makes the pressure on the upper wall in the porous region increase when the main flow in the porous region is completely supersonic. The calculations also suggest that three rods cause the widest suction area.展开更多
In the present work, the LBM （Lattice-Boltzmann method） is used to simulate natural convection in an inclined open ended square cavity filled with porous material. The cavity is submitted to heating and cooling from...In the present work, the LBM （Lattice-Boltzmann method） is used to simulate natural convection in an inclined open ended square cavity filled with porous material. The cavity is submitted to heating and cooling from two opposite sides with constant temperatures. The double-population approach is used to simulate hydrodynamic and thermal fields. The effect of a porous medium is taken into account by introducing the porosity into the equilibrium distribution function and adding a force term to the evolution equation. The Brinkman-Forchheimer equation, which includes the viscous and inertial terms, is applied to predict the heat transfer and fluid dynamics in the non-Darcy regime. The present model is validated with the previous literature. A comprehensive parametric study of natural convective flows is performed for various values of inclined angle.展开更多
In this study,an experiment was performed to clarify the flow field,in which the jets were normally injected into a main supersonic flow surrounded by a porous cavity,and this report figures out interaction between st...In this study,an experiment was performed to clarify the flow field,in which the jets were normally injected into a main supersonic flow surrounded by a porous cavity,and this report figures out interaction between starting shock wave and porous cavity.In the experiment,a porous cavity is attached to a main duct and jets and rods are inserted to the main duct on the porous cavity.To reveal this flow field,the thermal tuft probe was adopted to experimentally investigate the flow in the cavity.In the experiments,the effect of the porous cavity with jets or rods on the flow field is studied by means of visualization of schlieren method with a high speed camera and measurement of cavity flow with thermal tuft probe.As a results,frequency analysis of output of the thermal tuft probe revealed that some clear dominant frequencies were confirmed when the starting shock wave existed around the porous cavity in all cases of jets and rods arrangements.Moreover,visualization of schlieren method with a high speed camera clarified that a starting shock wave had the same dominant frequencies as that of the flow fluctuation in the cavity only around the cavity.展开更多
The primary focus of the present survey is to categorize the results of various investigations on the Shock/Boundary-Layer Interactions(SBLIs),their repercussions,and the effective ways to control them.The interaction...The primary focus of the present survey is to categorize the results of various investigations on the Shock/Boundary-Layer Interactions(SBLIs),their repercussions,and the effective ways to control them.The interactions of shock waves with the boundary layer are an important area of research due to their ubiquity in several applications ranging from transonic to hypersonic flows.Therefore,there is a need for a detailed inspection to understand the phenomena to predict its characteristics with certain accuracy.Considering this in mind,this article presents some key features of the physical nature of SBLIs,their consequences,and the control techniques in a sequential manner;in particular,the passive control techniques for the supersonic and hypersonic intakes are reviewed in detail.展开更多
文摘In this paper, some preliminary calculations and the experiments were performed to figure out the flow field, in which some rods were normally inserted into the main flow surrounded by a porous cavity. As a result, it is found that the starting shock wave severely interacts with the rods, the bow shock wave, its reflections, and the porous wall, which are numerically well predicted at some conditions. Moreover, inserting the rods makes the pressure on the upper wall in the porous region increase when the main flow in the porous region is completely supersonic. The calculations also suggest that three rods cause the widest suction area.
文摘In the present work, the LBM （Lattice-Boltzmann method） is used to simulate natural convection in an inclined open ended square cavity filled with porous material. The cavity is submitted to heating and cooling from two opposite sides with constant temperatures. The double-population approach is used to simulate hydrodynamic and thermal fields. The effect of a porous medium is taken into account by introducing the porosity into the equilibrium distribution function and adding a force term to the evolution equation. The Brinkman-Forchheimer equation, which includes the viscous and inertial terms, is applied to predict the heat transfer and fluid dynamics in the non-Darcy regime. The present model is validated with the previous literature. A comprehensive parametric study of natural convective flows is performed for various values of inclined angle.
文摘In this study,an experiment was performed to clarify the flow field,in which the jets were normally injected into a main supersonic flow surrounded by a porous cavity,and this report figures out interaction between starting shock wave and porous cavity.In the experiment,a porous cavity is attached to a main duct and jets and rods are inserted to the main duct on the porous cavity.To reveal this flow field,the thermal tuft probe was adopted to experimentally investigate the flow in the cavity.In the experiments,the effect of the porous cavity with jets or rods on the flow field is studied by means of visualization of schlieren method with a high speed camera and measurement of cavity flow with thermal tuft probe.As a results,frequency analysis of output of the thermal tuft probe revealed that some clear dominant frequencies were confirmed when the starting shock wave existed around the porous cavity in all cases of jets and rods arrangements.Moreover,visualization of schlieren method with a high speed camera clarified that a starting shock wave had the same dominant frequencies as that of the flow fluctuation in the cavity only around the cavity.
文摘The primary focus of the present survey is to categorize the results of various investigations on the Shock/Boundary-Layer Interactions(SBLIs),their repercussions,and the effective ways to control them.The interactions of shock waves with the boundary layer are an important area of research due to their ubiquity in several applications ranging from transonic to hypersonic flows.Therefore,there is a need for a detailed inspection to understand the phenomena to predict its characteristics with certain accuracy.Considering this in mind,this article presents some key features of the physical nature of SBLIs,their consequences,and the control techniques in a sequential manner;in particular,the passive control techniques for the supersonic and hypersonic intakes are reviewed in detail.
