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时间电压转换技术在超声流速计中的应用 被引量:5
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作者 雷亚辉 王之海 王向红 《应用科技》 CAS 2010年第8期23-25,30,共4页
时间到电压转换(TVC)技术已经广泛应用于雷达、通信、信号测量等领域.在此设计一套实用的电路系统应用于超声海流计系统,该电路系统主要由1个时序产生电路,1个时间电压转换电路以及1个模拟到数字电路组成.理论分析表明,通过此方法测量... 时间到电压转换(TVC)技术已经广泛应用于雷达、通信、信号测量等领域.在此设计一套实用的电路系统应用于超声海流计系统,该电路系统主要由1个时序产生电路,1个时间电压转换电路以及1个模拟到数字电路组成.理论分析表明,通过此方法测量脉冲到达时间间隔可以获得亚纳秒级时间分辨力.文中通过计算机辅助设计软件ORCAD仿真分析验证,该电路具有结构简单,精度高的特点. 展开更多
关键词 超声流速计 时间间隔测量 时间电压转换
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时间数字转换技术在三维海流计中的应用 被引量:2
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作者 雷亚辉 王向红 刘杰 《电子技术应用》 北大核心 2010年第4期61-64,共4页
随着电子技术的进步,通过数字电路实现微小时差的测量成为现实,时间到数字转换(TDC)技术已经广泛应用于测量等领域。本文介绍ACMA公司生产的TDC-GP2时间数字转换芯片,通过设计一套实用的电路系统应用于超声三维海流计系统。实验分析表明... 随着电子技术的进步,通过数字电路实现微小时差的测量成为现实,时间到数字转换(TDC)技术已经广泛应用于测量等领域。本文介绍ACMA公司生产的TDC-GP2时间数字转换芯片,通过设计一套实用的电路系统应用于超声三维海流计系统。实验分析表明,通过此方法测量脉冲到达时间间隔可以获得亚纳秒的时间分辨力,并可实现精确的三维流速测量,测量精度达到±3mm/s。 展开更多
关键词 超声流速计 流速测量 时间间隔测量 时间数字转换 TDC—GP2
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NUMERICAL SIMULATION OF SUPERSONIC AXISYMMETRIC FLOW OVER MISSILE AFTERBODY WITH JET EXHAUST USING POSITIVE SCHEMES 被引量:1
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作者 朱孙科 马大为 +1 位作者 陈二云 乐贵高 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第3期255-261,共7页
Supersonic axisymmetric jet flow over a missile afterbody containing exhaust jet is simulated using the second order accurate positive schemes method developed for solving the axisymmetric Euler equations based on the... Supersonic axisymmetric jet flow over a missile afterbody containing exhaust jet is simulated using the second order accurate positive schemes method developed for solving the axisymmetric Euler equations based on the 2-D conservation laws.Comparisons between the numerical results and the experimental measurements show excellent agreements.The computed results are in good agreement with the numerical solutions obtained by using third order accurate RKDG finite element method.The results show larger gradient at discontinuous points compared with those obtained by second order accurate TVD schemes.It indicates that the presented method is efficient and reliable for solving the axisymmetric jet with external freestream flows,and shows that the method captures shocks well without numerical noise. 展开更多
关键词 computational fluid dynamics supersonic flow positive schemes numerical simulation
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Combustion characteristics of supersonic strut-cavity combustor under plasma jet-assisted combustion 被引量:1
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作者 ZHANG Zhe JIN Xing XI Wen-xiong 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期311-324,共14页
Plasma jet has been widely used in supersonic combustor as an effective ignition and combustion assisted method,but currently it is mostly combined with the traditional wall fuel injection method,while the application... Plasma jet has been widely used in supersonic combustor as an effective ignition and combustion assisted method,but currently it is mostly combined with the traditional wall fuel injection method,while the application combined with the central fuel injection method is less.In order to expand the combustion range,the plasma jet was introduced into a strut-cavity combustor with an alternating-wedge.The effects of total pressure of strut fuel injection,total pressure of cavity fuel injection,total pressure of plasma jet injection and plasma jet media on the combustion characteristics were analyzed in supersonic flow by numerical calculations in a three-dimensional domain.The combustion field structure,wall pressure distribution,combustion efficiency and distribution of H2O at the exit of the combustor with different injection conditions were analyzed.The results show that the combustion efficiency decreases with the increase of the strut fuel injection total pressure.However,the combustion area downstream increases when the total pressure of the strut fuel injection increases within the proper range.The combustion range is expanded and the combustion efficiency is improved when the cavity fuel injection total pressure is increased within the range of 0.5−2.0 MPa,but a sharp drop in combustion efficiency can be found due to limited fuel mixing when the total injection pressure of the cavity fuel is excessively increased.With the increased total injection pressure of the plasma jet,the height of the cavity shear layer is raised and the equivalence ratio of the gas mixture in the cavity is improved.When the total pressure of the plasma jet is 1.25 MPa,the combustion efficiency reaches a maximum of 82.1%.The combustion-assisted effect of different plasma jet media is significantly different.When the medium of the plasma jet is O2,the combustion-assisted effect on the combustor is most significant. 展开更多
关键词 plasma jet STRUT CAVITY supersonic combustion numerical simulation combustion efficiency
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A hypersonic lift mechanism with decoupled lift and drag surfaces 被引量:7
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作者 XU YiZhe XU ZhiQi +3 位作者 LI ShaoGuang LI Juan BAI ChenYuan WU ZiNiu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第5期981-988,共8页
In the present study, we propose a novel lift mechanism for which the lifting surface produces only lift. This is achieved by mounting a two-dimensional shock-shock interaction generator below the lifting surface. The... In the present study, we propose a novel lift mechanism for which the lifting surface produces only lift. This is achieved by mounting a two-dimensional shock-shock interaction generator below the lifting surface. The shock-shock interaction theory in conjunction with a three dimensional correction and checked with computational fluid dynamics (CFD) is used to analyze the lift and drag forces as function of the geometrical parameters and inflow Mach number. Through this study, though limited to only inviscid flow, we conclude that it is possible to obtain a high lift to drag ratio by suitably arranging the shock interaction generator. 展开更多
关键词 lift mechanism shock-shock interaction lift-to-drag ratio
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