摘要：研究流体流动的最优形状设计问题,以流体力学中典型的stokes方程为状态方程,目标泛函使得总势能达到最小.将水平集方法与优化问题的灵敏度分析结果相结合以保证精确捕获优化形状的界面.用径向基函数来求解stokes方程和演化水平集函数的Hamilton-Jacobi方程.由于径向基函数方法是真正无网格的,因此与网格依赖的数值求解方法相比,所提算法具有更好的适应性也更容易实施.数值算例表明,所提算法可以高效、稳定地求解流体力学中的形状优化问题.

摘要：利用研究二阶问题的非协调类 Wilson任意四边形单元的特殊收敛性 ,通过新的技巧 ,并基于 Falk等人的基础 ,讨论了类 Wilson元对定常 stokes方程逼近的一种不需要试探函数满足 divu =0条件的有限元方法 .同时给出了与传统协调元及非协调元完全相同的最优误差估计 。

摘要：采用基于SST k-ω湍流模型耦合延迟脱体涡模拟技术(Delayed detached-eddy simulation,DDES)的SSTDDES模型,数值求解Navier-stokes方程。并针对低速流动问题,发展了基于隐式双时间步方法的低速预处理技术,用于数值模拟低速、高雷诺数湍流大分离流动问题。数值模拟了低速大迎角三角翼绕流及大迎角6∶1椭球绕流,观察到与物理现象相一致的旋涡特征,且得到的定量数值结果与实验数据相吻合。

摘要：This paper describes the optimization of the impeller having splitters for a turbo *** design variables,chord of splitter and pitch of splitter,are introduced to enhance the blower *** pressure and ef-ficiency are selected as an object function,and the optimization of the blower impeller is performed by a response surface method (RSM).Three-dimensional Navier-stokes equations are introduced to analyze the internal flow of the blower and to find the value of the object function for each *** the shape optimization of the splitters attached to the impeller in the turbo blower,pressure and efficiency at the design flow condition are suc-cessively increased by 5.9 percent and 17.9 percent respectively based on the reference *** higher blower efficiency obtained by optimization of impeller having splitters is mainly caused by reducing the number of im-peller blades and optimal design of splitters in the blade passage while pressure increase keeps almost the same with the reference *** the object function of pressure,pressure increase is obtained at the design and off-design conditions while efficiency keeps higher compared to the reference *** enhancement of blow-er performance is due to the reduction of reverse and circulation flows in the blade passage.

摘要：The shear-stress transport(SST)turbulence model is incorporated into Navier-stokes equations to simulate a turbomachinery flowfield.A staggered finite volume method is used to make the mean flow equations and turbulence model equations strongly coupled and enhance the stability of the numerical *** implicit treatment of the source terms is applied to the SST model.A steady state solution is obtained using five-stage Runge-Kutta time-stepping scheme with local time stepping and residual smoothing to accelerate convergence. The wall distance d,a key parameter in the SST model,is solved by a partial differential *** validations of the code are conducted on rotor 37,wp11 at design and off-design conditions by comparison with measurements and the Spalart-Allmaras(SA)turbulence *** flow within the tip is calculated with a multi-block grid.

摘要：真实煤气的效果在高压力和低温度是主导的，并且它被除完美的煤气的法律以外的状态的复杂方程建模。在液体蒸汽的附近批评的点，真实气体展出不平常的气体动态行为。在现在的工作，一个短暂波浪在单方的空缺脉搏试管回答被解决与 Peng-Robinson 热力学的模型一起合并的海军司烧方程模仿。计算液体动力学(CFD ) 结果为接触接口和冲击波显示出在完美的煤气的模型和真正的煤气的模型之间的显著偏差。基于真实气体，模型能帮助解决偏移量设计点的问题的波浪图。

摘要：Numerical investigations of the Darmstadt transonic single stage compressor (DTC), in the Rotor1-Stator1 configuration, aimed at advancing the understanding of the effect of different rotor tip gaps and transition modelling on the blade surfaces are presented. Steady three dimensional Reynolds Averaged Navier stokes (RANS) simulations were performed to obtain the flow fields for the different configurations at different operating conditions using the RANS-Solver TRACE. The stage geometry and the multi-block structured grid were generated by G3DMESH and a grid sensitivity analysis was conducted. For the clearance gap region, a fully gridded special H-grid was chosen. Comparisons were made between the flow characteristic at design speed, representative for a transonic flow regime, and at 65% speed, representative for a subsonic flow regime. The computations were used to analyse the flow phenomena through the tip clearance region for the different configurations and their impact on the performance of the compressor stage.

摘要：In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.

摘要：这份报纸在计划航行在常规波浪的手艺的数字模拟上论述研究。这允许保留高速度手艺的性能的海的精确估计。模拟集合在自由运动六度基于雷纳兹平均 Navier 司烧液体(RANSE VOF ) 的方程体积解答者。整修网孔技术和不可分的动态网孔方法被用来保证水动力学力量的好精确性和数字模拟的高效率。事件头波浪，倾斜的波浪和横梁波浪与三不同速度在模拟被产生(Fn =1.0， 1.5， 2.0 ) 。与波浪让计划手艺的性能来自不同方向的运动和海在流动解答者被显示。轮船设计者在驾驶在造高速度手艺的配置计划手艺的振幅和压力分发上把一个重音放在波浪的效果上。