In order to simulate the flow control problem by using Nanosecond Pulsed Dielectric Barrier Discharge(NSDBD),a one-zone inhomogeneous phenomenological model is constructed based on the experimental and theoretical res...In order to simulate the flow control problem by using Nanosecond Pulsed Dielectric Barrier Discharge(NSDBD),a one-zone inhomogeneous phenomenological model is constructed based on the experimental and theoretical results.The model is coupled with the unsteady Navier-Stokes equations,which can well predict the compression-expansion wave structures and wave speed compared with experimental results and can be applied to the simulation of the flow control by using NSDBD.The model is adopted to investigate the separation control over NACA0015 airfoil using the NSDBD plasma actuator.The separation-control mechanisms are revealed that the spanwise vortices produced by the plasma actuation play the key role.Each plasma actuation can produce a spanwise vortex around the separation point near the leading edge.The spanwise vortices make the separated free-shear layer unstable and shed away,move downstream along the upper wall,control the flow near the wall,and bring outer flow with high kinetic energy into the near wall region to realize the effective separation control over the upper surface of the airfoil.展开更多
脉冲功率的工业应用需要紧凑、灵活、稳定的脉冲功率源。高重频LTD是以此为目的发展的新技术,它所代表的脉冲叠加法与传统的脉冲压缩法存在很大的差异。本文介绍基于半导体开关的高重频LTD的基本方法和典型的实验结果。该LTD系统由30个...脉冲功率的工业应用需要紧凑、灵活、稳定的脉冲功率源。高重频LTD是以此为目的发展的新技术,它所代表的脉冲叠加法与传统的脉冲压缩法存在很大的差异。本文介绍基于半导体开关的高重频LTD的基本方法和典型的实验结果。该LTD系统由30个模块构成,每个模块采用24个MOSFET作为开关。实验结果表明：该LTD系统可以产生最高29 k V的输出电压和240 A的输出电流;脉冲宽度在50~170 ns范围内任意可调;控制模块的开关顺序可以方便地组合出不同的波形。LTD的模块化趋势和它的输出波形可调性是其主要优势,而在能量效率上有待进一步改善。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10972236,50906100)
文摘In order to simulate the flow control problem by using Nanosecond Pulsed Dielectric Barrier Discharge(NSDBD),a one-zone inhomogeneous phenomenological model is constructed based on the experimental and theoretical results.The model is coupled with the unsteady Navier-Stokes equations,which can well predict the compression-expansion wave structures and wave speed compared with experimental results and can be applied to the simulation of the flow control by using NSDBD.The model is adopted to investigate the separation control over NACA0015 airfoil using the NSDBD plasma actuator.The separation-control mechanisms are revealed that the spanwise vortices produced by the plasma actuation play the key role.Each plasma actuation can produce a spanwise vortex around the separation point near the leading edge.The spanwise vortices make the separated free-shear layer unstable and shed away,move downstream along the upper wall,control the flow near the wall,and bring outer flow with high kinetic energy into the near wall region to realize the effective separation control over the upper surface of the airfoil.
文摘脉冲功率的工业应用需要紧凑、灵活、稳定的脉冲功率源。高重频LTD是以此为目的发展的新技术,它所代表的脉冲叠加法与传统的脉冲压缩法存在很大的差异。本文介绍基于半导体开关的高重频LTD的基本方法和典型的实验结果。该LTD系统由30个模块构成,每个模块采用24个MOSFET作为开关。实验结果表明：该LTD系统可以产生最高29 k V的输出电压和240 A的输出电流;脉冲宽度在50~170 ns范围内任意可调;控制模块的开关顺序可以方便地组合出不同的波形。LTD的模块化趋势和它的输出波形可调性是其主要优势,而在能量效率上有待进一步改善。
