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数值模拟涡轴发动机燃烧室流场 总被引:1,自引:0,他引:1
本文运用贴体坐标系统对涡轴发动机燃烧室流场进行了数值模拟。采用TTM的非正交贴体坐标网格来处理燃烧室的曲线壁面边界。并把STMLE算法应用用到曲线坐标下求解各守恒方程,紊流粘度是用双方程k-ε模型来估算,紊流燃烧模型采用按简单的化学反应系统假设的Arrhenius-EBU模型,采用热流法辐射模型来估算辐射通量和燃烧室壁温及出口温度分布,计算结果令人满意。本文提供计算方法可供新型燃烧室设计方案选择用 相似文献
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对燃气轮机逆流式环形燃烧室,热态三维流场的数值模拟问题进行了研究,建立了三维计算模型,生成了数值计算网格。数值模拟研究表明,改变燃烧室的几个结构参数,可以得到更加合理的流场。通过对关键截面的流动分析,可以判断燃烧室设计的合理性,为进一步优化燃烧室结构设计、改善流场奠定了基础。 相似文献
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在实验和工程应用的基础上,介绍了利用辐射屏法对热网管道进行隔热保温中的确定辐射屏的层数及间隔的方法,并给出了40种不同管径或温度的计算结果,在工程应用中可予以采用。 相似文献
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文章叙述了排汽蜗壳扩压管流场的数值计算方法及发展趋势,介绍了东方汽轮机厂和西安交大合作开发用于扩压管流场计算的PHOENICS软件,用该软件对我厂300MW机组的低压排汽缸扩压管进行了数值优化。并与扩压管的吹风试验结果相比较,它们表现出较好的一致性。 相似文献
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本文根据叶轮部分的通流尺寸参数,首先采用UG NX软件生成初步的叶片及流道三维外形三维实体模型,并在IECM CFD软件中生成网格模型,然后在ANSYS-CFX软件中设置边界条件、选择合适的计算模型、设置收敛准则等,对涡轮叶轮部分进行流动数值模拟,获得了该部分的压力、速度等参数分布,并对其参数的分布情况进行了相应的分析.结果表明,各参数的变化规律对缩短叶轮机械设计周期、降低设计风险、改善叶轮机械气动性能以及探索叶轮机械气动设计的新方法提供了参考. 相似文献
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鉴于输电线路的电晕特性与导线表面及周围空间电场分布有着密切关系,基于ANSYS软件和MATLAB软件分别建立分裂导线-电晕笼模型,分别采用有限元法和模拟电荷法计算分析特高压电晕笼空间电场分布。结果表明,电晕笼内空间电场呈对称分布;子导线表面最大电场强度出现在子导线中心和分裂导线中心连线与外表面的交汇处;子导线周围电场强度随距子导线表面距离的增加而迅速减小;电晕笼内分裂导线仅在子导线周围有限范围内达到起晕场强;两种方法的计算结果相互印证,最大偏差不超过6.2%。 相似文献
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以某波瓣形混合器加力燃烧室三维模型为研究对象,采用CFD方法对模型进行数值分析,建模时重点对波瓣形混合器和环形火焰稳定器进行网格加密。以飞行试验工况点获取的低压涡轮后总温、总压结合Gasturb软件计算出加力燃烧室出口的总温、总压作为整体流场CFD计算的边界条件进行计算。计算结果表明:经过波瓣形混合器后,内、外涵气流能够在较短轴向距离充分混合,总压恢复系数最大为0.984;在接近出口处热混合效率达到0.516;气流经过环形火焰稳定器后,形成明显的低压回流区,且在出口处截面静压分布均匀,因此该加力燃烧室模型具有非加力状态流阻小的特点。通过对该型加力燃烧室流场特性分析,为加力燃烧室加力接通前内部参数获取提供技术支撑。 相似文献
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二维守恒元和求解元方法在两相爆轰流场计算中的应用 总被引:2,自引:0,他引:2
应用二维守恒元和求解元方法数值模拟脉冲爆轰发动机内汽油/空气两相燃烧转爆轰的过程.分析了爆轰波从开始产生到形成稳定的全过程.研究了点火能量对燃烧转爆轰过程的影响:点火能量越小,DDT时间越长;若点火能量过小就不能形成DDT.同时研究了液滴半径对爆轰参数的影响:液滴半径增大,爆轰波压力和速度随之减小,DDT时间增加;液滴半径过大,则爆轰波不能形成.爆轰波压力计算值与实验值两者趋势符合得较好. 相似文献
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In this research, the buckling behavior of functionally graded (FG) plates under thermal loading is investigated based on finite element analysis. It is assumed the plate is subjected to a uniform temperature rise across plate thickness. First-order shear deformation theory (FSDT) is utilized for developing the solution method. By using an appropriately designed mesh structure for a perforated plate, the critical thermal buckling temperature is obtained by numerical solution of the problem based on finite element method (FEM). The FG plate is perforated by multiple cutouts. The number of cutouts is assumed one, two, four, or six. Also different geometrical shapes of cutouts including triangle, square, rhombus, pentagon, hexagon, and circle are considered. The influence of the number of cutouts and their geometrical shapes on thermal buckling response is investigated. The effects of the number of sides of cutouts from three (triangle) to infinity (circle) are discussed. Two different boundary conditions are taken into account. Also the influences of the distance between the cutouts and the orientation of cutouts on critical buckling temperature are studied. In addition, the effects of the orientation of ellipse cutouts are studied. Some remarkable conclusions are gained that can be useful in practical applications. 相似文献
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采用有限元数值求解鳍片传热和传统相似理论计算方法相结合,得到符合经验数值的合理结果;对于工程实践具有参考价值。 相似文献
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In this work, thermal buckling analysis of symmetric and anti-symmetric laminated composite plates with a cut-out is presented. The plate is assumed to be subjected to a uniform temperature rise for different boundary conditions. The thermal buckling analysis is performed using the code developed in MATLAB software. The stiffness matrices and thermal force vector are derived according to first-order shear deformation theory (FSDT). To have more control on the mesh pattern around the cut-out, convenient meshes are manually constructed using a mesh generation algorithm in which mesh density around the hole can be controlled. The results of FEM code is compared with ABAQUS's solutions and with those available in the literature. After that, the effects of cut-out size, boundary conditions, plate aspect ratio, and stacking sequence on critical thermal buckling temperature are investigated for symmetric and anti-symmetric plates. Also, plates with cut-out located at positions other than the center of plate are investigated and useful conclusions are derived from the numerical results. 相似文献
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Heat and Mass Transfer Flow of a Nanofluid over an Inclined Plate under Enhanced Boundary Conditions with Magnetic Field and Thermal Radiation 下载免费PDF全文
This article presents the magnetohydrodynamic boundary layer flow, heat and mass transfer characteristics of a nanofluid over an inclined porous vertical plate with thermal radiation and chemical reaction. The new enhanced concentration boundary condition on the surface of the wall is considered in this analysis. The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations using the similarity variables and are solved numerically using the finite element method. The effect of key parameters such as magnetic parameter (M), buoyancy ratio (Nr), Prandtl number (Pr), thermal radiation (R), Brownian motion (Nb), thermophoresis (Nt), Lewis number (Le), and chemical reaction parameter (Cr) on velocity, temperature, and concentration distributions is discussed in detail and the results are shown graphically. Furthermore, the impact of these parameters on skin‐friction coefficient, Nusselt number, and Sherwood number is also investigated and the results are shown in tabular form. The developed algorithm is validated with works published previously and was found to be in good agreement. The thermal boundary layer thickness is elevated, whereas the solutal boundary layer thickness retards with the improving values of the Brownian motion parameter (Nb). The rates of nondimensional temperature and concentration both decelerate with higher values of the thermophoresis parameter (Nt). 相似文献
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三相共箱式气体绝缘母线的热计算及散热性能研究对于其可靠性设计及在线监测具有重要意义。根据流体力学理论,采用流体多组分有限元法对三相共箱式气体绝缘母线进行热计算,利用映射网格划分实现电磁场、温度场和流体场的间隔耦合,综合考虑了母线外壳内外气体的流动和温度变化特性。采用流体单组分有限元法、流体多组分有限元法、传热学解析公式法三种方法进行计算,并对比分析了计算结果与试验结果的精度。结果表明,多组分有限元法与试验结果最为接近,为气体绝缘母线的设计及在线监测提供了理论基础。 相似文献