文献翻译-履带车辆驱动部件电力传动系统结构的热流场的分析

外文参考文献及翻译Analysis on Thermal Current Field in Powertrain Cabinof Tracked Vehicles With Electric Transmission SystemConfiguration-2Abstract：The electric transmission system congfiguration-2 is one of the main electric drives for tracked vehiclesThe geometrical model for the powertrain cabin is established and the preliminary design for its cooling system is implementedThe mathematic model is established for therma1 current field computationsimulation and analysis in the power train cabinThe three-dimensional structure of the powertrain cabin is optimizedThe validity of the cooling system design is provedThe foundation for optimizing the whole electric transmission system configuration is laidKey Words：dynamic and electric engineering；tracked vehicle；electric transmission；modeling；thermal current field；Structure optimizationIntroductionThe electric transmission system configuration-2is a main form of the electric drive for tracked vehicles， which is defined against configuration-1Configuration-1 consists of two driving motors in both left and right sides of the vehicle body，powered by the enginegenerator，while configuration-2 consists of a driving motor and a turning motor，and it is a typical dualpower transmission mechanism. The block diagram of configuration-2 is showed in Fig1There is a power feedback path of cross shaft on the configuration-2，and the inner power can be fed back to the outer when it is turning，so overloading capacity and frequency of the driving motor falls significantly，and the turning capability becomes betterThe powertrain cabin of the electric drive configuration-2 is composed of diesel engine，electric generator， electric motors，intercooler，rectifier，converter and etcThe efficiency of armored vehicles cooling system is dependent on the thermal current fieldTherefore，the computation and analysis of the flowfield are important for investigating configuration2，they form the basis for system performance and structure optimization，and they are also useful in systemdemonstration and evaluation1、Modeling on Powertrain Cabin andComputation of the Thermal Current Field11 Geometric Model of the Powertrain Cabin and Its Cooling System DesignThe geometric modeling for the powertrain cabin and the preliminary design for the cooling system arethe foundation for computing the thermal current field in the powertrain cabinWe can design the sizes of the key components and establish the three-dimensional structure for the powertrain cabin through modeling， controlling and simulation of the enginegenerators and the driving system of the electric transmission system -2The model is shown in Fig2The model can be imported into the PHOENICS environment and the geometric model is shown in Fig3In the geometric model，the Xaxis Yaxis and Zaxis are the back，right and upside of the tracked vehicle respectively and the origin of the coordinate is located at the leftfront point of the external surface of the bottom of the vehicle According to theoretical calculations and the heat dissipation requirements for the powertrain cabin, the electric drive cooling system is divided into high and lowtemperature cooling lops It is shown in Fig.4.12 Mathematical Modeling and Boundary Conditions for the Powertrain CabinAccording to the real structure of configuration-2standard-model control equation 3-5 is adopted in the mathematical model， which includes the quality control conservation equation，the momentum conservation equation ，the energy conservation equationthe turbulence kinetic energy equation and theturbulence kinetic energy dissipated rate equation.Under preliminary prediction， the air speed in the local powertrain cabin is high，and its Mach number is more than 015In order to keep the control equations closed， the compressibility of the air and the change of its material parameters must be considered .The changes of gas density can be described by the ideal gas state equation，vizP= RT (where R is molar gas constant，R=287 J(kgK)in air)The airs kinematic viscosity ， heat capacity at constant pressure cp and thermal conductivity are defined as fixed valuesThe material parameters of the dry air at 60c ，viz189710 -5m-2/ s，1005 kJ (kgK) and 0029 W(mK)are taken as approximations of ， cp and According to the empirical factor，the coefficient of controlling equation is valued in Table 1Table 1 The coefficients of standard k-model controlling equation Among them， c ，c l ，c 2 are constant coefficients；P r is the Prandtl number of turbulence about ；P r is the Prandtl number of turbulence about ；P rT is the Prandtl number of turbulenceExcept the radiator，the other solid surface thermal boundary conditions adopt the first boundary condition in the mode1The surface temperature of the components is similar to its exit temperature of the cooling water(referred to reference table 2)The local surface operation temperature of the ventpipe can reach 600700 ,and the general surface temperature can be limited 130 180 with heat shielding material outside the pipe，then we presume that the surface temperature of vent，pipe is close to 150The temperature of the other components and the wall of the cabin are presumed as environment temperatureThe thermal boundary of radiator adopts the second boundary condition，and the total heat dissipation capacity of the high-temperature circuit radiator is 180 kW ，while that of the lowtemperature circuit radiator is 90 kW The fans are simulated by the FAN in the PHOENICSThe shutter is simulated by the multi-thin plate combination provided by PHOENICS，and the radiator is simulated by the BLOCK-AGETable 2 The heat dissipating capacity and the surface temperature of main partsAccording to the difference of the airflow among various parts，we can use different grid spacing，such as using dense grids in intake，vent windows and radiators where the airflow rate changes greatlyThe whole area is divided into 73 x 69 x 65 grids，and the number of the nodes is 327 405The airflow in the inlet is assumed as the environment atmospheric pressure，and that is p = 1.013 x105PaThe temperature in the inlet is close to environment temperature To,viz.T= To .The turbulence coefficients k andin the inlet boundary are as followsLkcIu2/34/Where is the average speed of the incoming flow in the inlet(ms)；L is the characteristic dimension of equivalent water diameter in the inlet boundary(m)；I is the turbulence intensity，defined as the ratio of the square root of ripple quantity of velocity and the average velocity of flow ；c is constant coefficient，valued 009Except the air pressure，the value of other variable gradients in the outlet boundary is 0.2 Comparisons and Analysis of Calculation ResultBased on the previous geometric and mathematical model，the results were analyzed by adjusting the position of multiple components，simulating and calculating the powertrain cabin21 Position Effect of the High and Low Temperature Radiator on Powertrain Cabin Thermal Current FieldIn Fig 5，(a)is the result of the temperature current field vertical to Xaxis，and(c)is the result of the speed current field vertical to Yaxis，while the high temperature radiator is close to exhaust exit and rectifier is located at the rear of cabin(b) is the result of the temperature current field vertica1 to Xaxis and(d)is the result of the speed current field vertically to Yaxis，while the low temperature radiator is close to exhaust exit and rectifier is located at the rear of cabin.Through comparison and analysis of temperature field vertical to X axis， when the high temperature radiator is close to exhaust exit， the temperature of detecting point is 9414 ，the average temperature of the section is 5288 However， when the low temperature radiator is close to exhaust exit，the temperature of the same detecting point is 5054 ,the average temperature of the section is 4785 It seems that the performance is better of the latter，but after analyzing(c)and(d)about speed current field，we can get a contrary conclusionIt is very clear that when low temperature radiator comes close to exhaust exit， the speed of detecting point and the average speed of the section reaches 537 10 m 3/s and 46410 m 3/s respectively, which is far away from realityTherefore ，the scheme of low temperature radiator is not better than that of high temperature radiator at closing to exhaust exit，especially when the low temperature cooling current exit has not been establishedAn important reason is that the hot air is circulated in the powertrain cabin at first，and ejected out of it in the end22 Effect of the Position of Rectifier on the Powertrain Cabin Thermal Current FieldAccording to the analysis of the last section，we can conclude that the high temperature radiator shall be close to exhaust exitThus，we can change theposition of other components， and confirm the position analysis of main components by comparing and analyzing the calculation results In this section，we take the position of rectifier as an example to analyze the layout while the high temperature radiator is near exhaust exitIn Fig6，(a)and(e)are temperature currentfields vertical to Xaxis and Zaxis respectively，while the rectifier is at the rear of the powertrain cabin(b) and(d)are temperature current field vertical to X axis and Zaxis respectively，while the rectifier is at the front of the powertrain cabinThrough comparison， when the rectifier comes close to the rear(basically in a line with the radiator)，the average temperature and the probe temperature are higherthan those close to the frontIn Fig 7，(a)and(c)are speed field vertical to Y-axis and Z- axis respectively when the rectifier is at the rear of the powertrain cabin(b) and (d)are speed field respectively vertically to Y-axis and Z-axis，when the rectifier is at the front of the dynamics cabinThrough comparison，at the same probe point and section ， when the rectifier comes close to the front，the current speed is 013 m 2 /s(vertical to Y axis)，higher than that to the rear ，but the average current speed is 0123 m 3 /s(vertical to Y axis)and 0077 m 3 /s(vertical to Z axis)lower，so we tend to make the rectifier close to the front in order to make it dissipate heat more effectivelyThe main cause lies in Fig7(c)，(d) In the section vertical to Zaxis，air passes through radiator and enters powertrain cabin，and flows to the front electromotor and transmission shaft along the right side of powertrain cabin， then reaches the place in a line with radiator along theleft side，at last discharges from exhaust exit along the bottom It is obvious that only a smal1 fraction of air passes through the front of the powertrain cabin in Fig7，so we must pay attention to reducing the resistance of the air and the surface temperature of the main parts in the structure design as much as possible.23 Effect of Fan Flow Velocity on the Powertrain Cabin Thermal Current FieldIn the course of devising cooling system，the demand of heat dissipation will be satisfied in theory when fans power is beyond 10 m3 /s The data which are at the same probe point and same section (coordinates X =2767 5，Y ：227，Z =11)are obtained as shown in Table 3 after simulationIn Table 3，the average temperature discrepancy is approximately 1 at all sections in the powertrain cabinBut since all data are beyond 50 ,the effect of heat dissipation of the components of powertrain cabin will be weakenedThrough adjusting the coordinates of detecting point，the measured temperature under high temperature radiator is7 1 57 ,and the temperature under low temperature radiator is 60 95 ,corresponding to the supposed temperatures which are 70 and 60 respectively f in the condition of12 m3/s)Although both kinds of fans can meet the demand，due to our simple model，we neglected many trivial factors existing in the real system in favor of modeling，simulation and calculationFor example ，the layout of pipeline and circuit may effect the pressure fall and resistance，so we suggest adopting the fan with 12 m3 /s power for margin3 Conclusions1)The design of radiator is validated and i its tentative temperature is feasibleAt the same time，the diathermanous demand of the system is met by the cooling loop2)By simulating and adjusting the position of the main parts in the powertrain cabin， the three-dimensional structure of armored vehicles and the position of the high and low temperature cooling loops are established3) The surface temperatures of the main parts are the major factors to affect powertrain cabin thermal current field significantly， and therefore thesetemperatures must be kept as low as possible，especially for the ventpipe of the diesel engine，whose temperature is rather high，and relevant heat shielding is necessary4)The air does not circulate fluently in the front part of the powertrain cabin，and only a small fraction of cool air passes through the motor and converter，the flowpilot should be redesigned to reduce pressure drop and air resistance in the front section外文参考文献译文履带车辆驱动部件电力传动系统结构的热流场的分析摘要：电力传动系统是履带车辆主要驱动之一。驱动部件建立数学模型，就可初步实现对冷却系统的设计。数学模型建立确定热流场的计算在驱动部件中的仿真和分析。（实现了）驱动部件三维结构的最佳化证明了冷却系统设计的有效性，确定了整个的电力传动系统结构最佳化。关键词：动力和电力工程学；履带车辆；电力传动；建模；热流场；最优化设计介绍电力传输系统是履带车辆电力驱动的主要组成部分，因此它不能与整个结构相违背。在履带行走部件的设计中主要存在以下两种结构：结构-1中履带行走车辆的行走部件由总电动机直接同时驱动的左右两个行走马达组成的；结构-2是由一个行走马达和一个转向马达组成的一种典型双重-电力传动机械装置组成如图一所示的为结构-2 的方块图，在结构-2中有一个电源反馈回路在横轴，而且当它转向时，内部动力信号被反馈回到外部输出装置，因此当车辆过载和行走马达的频率发生异常时可以被显示出来，而且转向的平稳性变成得更好。结构-2 动力部件的电力驱动系统主要由柴油机、驱动电动机、液压马达、冷热气自动调节机、整流器、转向装置及其他部分组成。履带行走冷却系统的效率主要依赖于热流场。因此，在设计以结构-2 为基础的履带行走装置计算和分析热流场有很重要的作用，它们整个行走系统运转和结构设计最佳化的基础，并且它们在系统示范和评估方面也是有用的。1、行走装置驱动部件的建模和热流场计算1.1驱动部件的数学建模和冷却系统设计行走装置的驱动部件数学建模和冷却系统的初步设计是驱动部件热流场计算的基础。首先我们为行走装置的驱动部件建模、控制、电力传动和驱动装置的电力传输系统仿真，而设计关键部分的尺寸和确定三维空间的结构。如图2所示模型。模型可以输入进 PHOENICS（一个以MATHLAB为基础的建模程序）中，如图三所示的为结构的数学模型。在数学模型中，X轴、 Y轴和 Z轴分别表示是行走装置的后部、右部和上部，而且相同的坐标轴起源位于车辆底部外面表面左边-最前点。依照理论上的计算和行走装置散热需求, 电力驱动的冷却系统被区分为高、低温度线如图4所示.1.2行走驱动装置建立数学模型和确定边界条件依照结构-2 的真正结构，在数学上的模型建立中采用-标准的控制平衡模型，它包括质量守恒方程定律、动量守恒方程定律、能量守恒方程定律、干扰动能方程定律和干扰动能消散估计方程定律。在初步的预测之下，在驱动部件内的空气流速是很高的，而且它的马赫数（空气流速与音速的比值）是超过0.15,为了使闭环控制系统平衡，一定要考虑空气的压缩率和它的物质参数（指空气的质量）的变化。气体密度的变化能用理想气体状态方程描述，公式：P= RT(这里R是气体摩尔常数，在空气中R=287 J(kgK)空气的运动学黏性，热容量在恒定压力 c p 和热传导性定义为定量值干燥空气的物质参数在60 c时 ， c p 和 的近似值为189710 -5m-2/ s、1005 kJ(kgK)和0029 W (mK) 。依照经验因数，闭环控制方程系数如表 1 所示：在他们之中， c ，c l ，c 2 是常量系数；P r 是关于的干扰关系函数； Pr 是关于 的干扰关系函数，目是关于； P rT 关于P的干扰关系函数 除了散热器以外，另一个固体表面的热量边界条件采用第一个数学模型中的边界条件。表面温度的大小与它的输出口温度冷却水 (参考表2)类似运转时出烟管的表面温度能到达 600-700 ,而一般的表面温度与热屏隔材料只能是限制在 130-180。在管之外，然后我们假定出烟管的表面温度，是接近 150假定其他部件的温度和行走部件箱体铸壁就是履带车辆所在的环境温度。散热器的热量边界条件采用第二边界条件，并且驱动部件总热量散热电路能力：高温时散热器的最大功率是180KW，低温时散热器的功率是 90KW在 PHOENICS 中模拟风扇的相关参数，PHOENICS的软件薄面化合物模仿风门，用BLOCK-AGE模拟散热器。依照在各种不同零配件之中气流的不同，我们能使用不同的格栏间隔，像是在吸气口、出气口和散热器气流突变的地方使用密集的格栏间隔。整个面积被区分为 73 69 65个格栏，而且节的数目是327405。在吸气口的气流假定为环境大气的压力，因此p=1.013 x 10 5Pa在吸气口的温度接近环境温度， T= To。在吸气口干扰系数 k 和的边界条件如下所示：LcIuk2/34/这里的 是指吸气口气流进入时的平均温度(ms)，L吸气口的相对于当量水平线的基准尺寸（吸气口相对于水平线的高度）（m）；I是紊流强度，指的是紊流速度的平方根和平均速度 的比值；c 是常量系数，估计定位0.09除了气压以外，出气口的其他变量边界条件为 0 。2、比较和分析计算结果基于前节的几何学和数学上的模型，得到了分析调节若干组成零件的位置，驱动部件的模拟与计算的结果。2.1驱动部件热流场高温和低温散热器的位置效应如图5所示，(a)是X轴表示温度计算结果，(c)是 Y轴表示速度计算结果，当温度最高时散热器温度接近排气口的最值，而且整流器位于热流场的最大值，（b）是 X轴温度计算结果，(d) 是与Y轴垂直表示当前速度结果，当温度最低时散热器接近吸气口的最值，而且整流器位于