对双环腔燃烧室进行优化设计,研究双环腔燃烧室的性能及其污染物排放规律。参考国外某双环腔燃烧室的结构,将其火焰筒结构设计为并联式双环腔结构。改变主燃区、预燃区旋流器的结构,优化主燃孔、掺混孔的位置及孔径大小,进行流动、燃烧...对双环腔燃烧室进行优化设计,研究双环腔燃烧室的性能及其污染物排放规律。参考国外某双环腔燃烧室的结构,将其火焰筒结构设计为并联式双环腔结构。改变主燃区、预燃区旋流器的结构,优化主燃孔、掺混孔的位置及孔径大小,进行流动、燃烧及排放数值模拟。获得了不同结构双环腔燃烧室的总压恢复系数、燃烧效率、燃烧室出口温度分布系数、污染排放等性能参数。对比分析不同结构双环腔燃烧室的计算结果。结果表明:经过优化后的双环腔燃烧室出口具有更高的总压恢复系数和燃烧效率,更好的温度分布,更低的 CO 和 NO_x 排放。展开更多
Based on the theory of EHD (electronhydrodynamic),a simplified volume forcemodel is applied to simulation to analyze the traits of plasma flow control in flow field,in whichthe cold plasma is generated by a DDD (diele...Based on the theory of EHD (electronhydrodynamic),a simplified volume forcemodel is applied to simulation to analyze the traits of plasma flow control in flow field,in whichthe cold plasma is generated by a DDD (dielectric-barrier-discharge) actuator.With the paraelectricaction of volume force in electric field,acceleration characteristics of the plasma flow areinvestigated for different excitation intensities of RF (radio frequency) power for the actuator.Furthermore,the plasma acceleration leads to an asymmetric distribution of flow field,and henceinduces the deflection of jet plume,then results in a significant deflection angle of 6.26° thrustvectoringeffect.It appears that the plasma flow control technology is a new tentative method forthe thrust-vectoring control of a space vehicle.展开更多
An electrohydrodynamic (EHD) method,which is based on glow discharge plasma,is presented for flow control in an S-shaped duct.The research subject is an expanding channel with a constant width and a rectangular cross ...An electrohydrodynamic (EHD) method,which is based on glow discharge plasma,is presented for flow control in an S-shaped duct.The research subject is an expanding channel with a constant width and a rectangular cross section.An equivalent divergence angle and basic function are introduced to build the three-dimensional model.Subsequently,the plasma physical models are simplified as the effects of electrical body force and work (done by the force) on the fluid near the wall.With the aid of FLUENT software,the source terms of momentum and energy are added to the Navier-Stokes equation.Finally,the original performance of three models (A,B and C) is studied,in which model A demonstrates better performance.Then EHD control based on model A is discussed.The results show that the EHD method is an effective way of reducing flow loss and improving uniformity at the duct exit.The innovation in this study is the assessment of the EHD control effect on the flow in an S-shaped duct.Both the parametric modeling of the S-shaped duct and the simplified models of plasma provide valuable information for future research on aircraft inlet ducts.展开更多
This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2C...This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.展开更多
This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an a...This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.展开更多
文摘对双环腔燃烧室进行优化设计,研究双环腔燃烧室的性能及其污染物排放规律。参考国外某双环腔燃烧室的结构,将其火焰筒结构设计为并联式双环腔结构。改变主燃区、预燃区旋流器的结构,优化主燃孔、掺混孔的位置及孔径大小,进行流动、燃烧及排放数值模拟。获得了不同结构双环腔燃烧室的总压恢复系数、燃烧效率、燃烧室出口温度分布系数、污染排放等性能参数。对比分析不同结构双环腔燃烧室的计算结果。结果表明:经过优化后的双环腔燃烧室出口具有更高的总压恢复系数和燃烧效率,更好的温度分布,更低的 CO 和 NO_x 排放。
基金supported by National Natural Science Foundation of China (No.90716025)
文摘Based on the theory of EHD (electronhydrodynamic),a simplified volume forcemodel is applied to simulation to analyze the traits of plasma flow control in flow field,in whichthe cold plasma is generated by a DDD (dielectric-barrier-discharge) actuator.With the paraelectricaction of volume force in electric field,acceleration characteristics of the plasma flow areinvestigated for different excitation intensities of RF (radio frequency) power for the actuator.Furthermore,the plasma acceleration leads to an asymmetric distribution of flow field,and henceinduces the deflection of jet plume,then results in a significant deflection angle of 6.26° thrustvectoringeffect.It appears that the plasma flow control technology is a new tentative method forthe thrust-vectoring control of a space vehicle.
文摘An electrohydrodynamic (EHD) method,which is based on glow discharge plasma,is presented for flow control in an S-shaped duct.The research subject is an expanding channel with a constant width and a rectangular cross section.An equivalent divergence angle and basic function are introduced to build the three-dimensional model.Subsequently,the plasma physical models are simplified as the effects of electrical body force and work (done by the force) on the fluid near the wall.With the aid of FLUENT software,the source terms of momentum and energy are added to the Navier-Stokes equation.Finally,the original performance of three models (A,B and C) is studied,in which model A demonstrates better performance.Then EHD control based on model A is discussed.The results show that the EHD method is an effective way of reducing flow loss and improving uniformity at the duct exit.The innovation in this study is the assessment of the EHD control effect on the flow in an S-shaped duct.Both the parametric modeling of the S-shaped duct and the simplified models of plasma provide valuable information for future research on aircraft inlet ducts.
基金supported by National Natural Science Foundation of China (No. 90716025)
文摘This paper is devoted to experimentally investigating the influence of magnetic field intensity and gas temperature on the plasma jet deflection controlled by magneto hydrodynamics. The catalytic ionization seed CS_2CO_3 is injected into combustion gas by artificial forced ionization to obtain plasma fluid on a high-temperature magnetic fluid experimental platform. The plasma jet was deflected under the effect of an external magnetic field, forming a thrust-vector effect.Magnesium oxide was selected as a tracer particle, and a two-dimensional image of the jet flow field was collected using the particle image velocimetry(PIV) measurement method. Through image processing and velocity vector analysis of the flow field, the value of the jet deflection angle was obtained quantitatively to evaluate the thrust-vector effect. The variation of the jet deflection angle with the magnetic field intensity and gas temperature was studied under different experimental conditions. Experimental results show that the jet deflection angle increased gradually with a rise in gas temperature and then increased substantially when the gas temperature exceeded 2300 K. The jet deflection angle also increased with an increase in magnetic induction intensity. Experiments demonstrate it is feasible to use PIV test technology to study the thrust vector under magnetic control conditions.
基金supported by National Natural Science Foundation of China (No.90716025)
文摘This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.
