Numerical simulation of flows over complete aircraft using block structured grid systems

2008 ◽  
pp. 554-555 ◽  
Author(s):  
Keisuke Sawada
Keyword(s):  
Numerical Simulation ◽  
Grid Systems ◽  
Structured Grid ◽  
Block Structured

Numerical Simulation of a Padded Finger Seal

2008 ◽  
Author(s):  
Guoqiang Yue ◽  
Qun Zheng ◽  
Rongkai Zhu
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Fluid Flows ◽  
Bottom Surface ◽  
Commercial Software ◽  
Structured Grid ◽  
Fluid Field ◽  
Software Packages ◽  
Icem Cfd ◽  
Block Structured

The leakage of turbomachinery is important to its performances. A type of non-contacting finger seal was introduced in this paper. The fluid flows through the finger seal are numerically analyzed. Multi-block structured grid of the fluid field was generated by commercial software packages ICEM CFD. The leakage and the pressure distribution on pads’ bottom surface were simulated by CFX, and the displacement of the pad was calculated in ANSYS.

Numerical Simulation Study on the Asymmetric Structures of Oscillatory Flow Field in a Baffled Tube Reactor

2004 ◽  
Author(s):  
Yong-Wen Wu ◽  
Jia Wu
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flows ◽  
Oscillatory Flow ◽  
Numerical Technique ◽  
Three Dimensional ◽  
Structured Grid ◽  
Tube Reactor ◽  
Oscillating Boundary ◽  
The Asymmetry ◽  
Laminar And Turbulent Flows

The oscillatory flow in a baffled tube reactor provides a significant enhancement of radial transfer of momentum, heat and mass and a good control of axial back mixing at a wide range of net flow rate. But little has been known about reliable details of the three-dimensional structure of flow field in this kind of flow because most published studies in the area were based on the two-dimensional simulation techniques. This paper implemented a three-dimensional numerical simulation study on the asymmetry of flow pattern in the baffled tube reactor which was observed experimentally. A systematic study by numerical simulation was carried out which covered a range of oscillatory Reynolds number (Reo) from 100 to 5,000 and employed models respectively for laminar and turbulent flows. It was found in the simulation that under symmetric boundary conditions the transition from axially symmetric flow to asymmetric one depended on the numerical technique employed in simulation. With a structured grid frame the transition occurred at Reo much greater than that with an unstructured grid frame, for both laminar and turbulent flows. It is not rational that the onset of the transition changes with the accuracy of numerical technique. Based on the simulation results, it was postulated that the asymmetry appeared in simulations with symmetric boundary conditions might result from the accumulation of calculation errors but the asymmetry observed in experiments might result from the slight asymmetry of geometry which exists inevitably in any experiment apparatus. To explore the influence of the slight asymmetry of geometry, the effect of the eccentricity of baffles and the declination of oscillating boundary were studied by use of the finite volume method with a structured grid and adaptive time steps. The simulation result showed that both the eccentricity of baffles and the declination of oscillating boundary have obvious influence on the asymmetry of flow patterns for laminar and turbulent flow. More details were discussed in the paper.

The Hinge Moment Optimization of Rudder Base on CFD Numerical Simulation

2013 ◽  
Vol 397-400 ◽  
pp. 218-221
Author(s):  
Nan Zhang ◽  
Yue Zhang
Keyword(s):  
Numerical Simulation ◽  
Angle Of Attack ◽  
Special Design ◽  
Optimization Program ◽  
Airfoil Optimization ◽  
Structured Grid ◽  
Simulation Calculation ◽  
Cfd Numerical Simulation ◽  
Grid Division ◽  
Rudder Angle

The paper introduce structured grid division, use CFD numerical simulation and FLUNET software to conduct the simulation calculation for the hinge moment of rudder. To illustrate the problem, we select two unused plane airfoil An axis-symmetric rudder, one for the special design of the plane rudder. Calculated at 0.4 ~ 1.8Ma, different rudder angle, angle of attack different hinge moment value, and compare them ultimately come to a flat airfoil optimization program, making the steering hinge moment to meet the indicators proposed.

A Hybrid Dynamic Mesh Generation Method for Multi-Block Structured Grid

2017 ◽  
Vol 9 (4) ◽  
pp. 887-903 ◽  
Author(s):  
Hao Chen ◽  
Zhiliang Lu ◽  
Tongqing Guo
Keyword(s):  
Mesh Generation ◽  
Three Dimensional ◽  
Dynamic Mesh ◽  
Efficient Manner ◽  
Structured Grid ◽  
Transfinite Interpolation ◽  
Grid Deformation ◽  
Distance Weighting ◽  
Inverse Distance ◽  
Block Structured

AbstractIn this paper, a hybrid dynamic mesh generation method for multi-block structured grid is presented based on inverse distance weighting (IDW) interpolation and transfinite interpolation (TFI). The major advantage of the algorithm is that it maintains the effectiveness of TFI, while possessing the ability to deal with multi-block structured grid from the IDW method. In this approach, dynamic mesh generation is made in two steps. At first, all domain vertexes with known deformation are selected as sample points and IDW interpolation is applied to get the grid deformation on domain edges. Then, an arc-length-based TFI is employed to efficiently calculate the grid deformation on block faces and inside each block. The present approach can be well applied to both two-dimensional (2D) and three-dimensional (3D) problems. The proposed method has been well-validated by several test cases. Numerical results show that dynamic meshes with high quality can be generated in an accurate and efficient manner.

scholarly journals GPU Parallelization Nested Decomposition Method for Solving Large Linear Systems in Reservoir Numerical Simulation

2019 ◽  
Vol 23 (3) ◽  
pp. 249-257
Author(s):  
Xin Shi ◽  
Yuan Di
Keyword(s):  
Numerical Simulation ◽  
Parallel Algorithm ◽  
Linear Equations ◽  
Parallel Architecture ◽  
Residual Pressure ◽  
Linear Solution ◽  
Structured Grid ◽  
Grid Model ◽  
Preprocessing Method ◽  
Large Linear Systems

This paper designs a highly parallel Nested Factorization (NF) to solve large linear equations generated in reservoir numerical simulation problems. The NF method is a traditional linear solution preprocessing method for reservoir numerical simulation problems, and has regained attention in recent years due to its potential to extend to parallel architectures such as GPUs (Graphics Processor Units). The parallel algorithm of this paper is based on the MPNF (Massively Parallel Nested Factorization) framework proposed by Appleya (Appleyard, Appleyard, Wakefield, & Desitter, 2011). The MPNF algorithm designed in this paper focuses on its efficient implementation on the GPU parallel architecture. Its features include: using a custom matrix structure to achieve merge access, improving access bottlenecks and improving the efficiency of the SpMV algorithm. It is also applicable to the two-stage preprocessing method CPR. (Constrain Pressure Residual) pressure solution and global preprocessing stage; the MPNF method is extended to the solution of 2.5-dimensional unstructured grid problem. The parallel algorithm in this paper has been integrated into the reservoir numerical simulator. For the SPE10 (million grid, highly heterogeneous) standard example, the GPU-based parallel NF algorithm is in the structured grid model and the equivalent 2.5-dimensional non- On the structured grid model, compared with the serial version of the NF method, the acceleration ratios of 19.8 and 17.0 times were obtained respectively; compared with the mainstream serial solution method, the efficiency was also improved by 2 to 3 times.

scholarly journals Numerical Simulation of Rotor in Hover and Forward Flight

2018 ◽  
Vol 179 ◽  
pp. 03011
Author(s):  
Qinghe Zhao
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Flow Field ◽  
Moving Grid ◽  
Steady State Flow ◽  
Forward Flight ◽  
Numerical Simulation Result ◽  
Structured Grid ◽  
Pressure Distributions ◽  
Good Agreement

The flow around rotor is numerical simulated in hover and forward flight based on multi-structured grid. In hover the flow field can be transformed into a steady-state flow field in the rotating coordinate system. The experimental data of Caradonna and Tung rotor is used to verify the numerical simulation result. The numerical results compare well with the experimental data for both non-lifting and lifting cases. Non-lifting forward flight is simulated and the prediction capabilities have been validated through the ONERA two-blade rotor. The pressure distributions of different positions under different azimuth angles are compared, which is in good agreement with the experimental data. There is unsteady shock wave when forward flight. Dual-time method is used to obtain unsteady flow field with rigid moving grid in the inertial system.

CPU/GPU computing for a multi-block structured grid based high-order flow solver on a large heterogeneous system

2013 ◽  
Vol 17 (2) ◽  
pp. 255-270 ◽  
Author(s):  
Wei Cao ◽  
Chuan-fu Xu ◽  
Zheng-hua Wang ◽  
Lu Yao ◽  
Hua-yong Liu
Keyword(s):  
Heterogeneous System ◽  
Gpu Computing ◽  
High Order ◽  
Order Flow ◽  
Flow Solver ◽  
Structured Grid ◽  
Grid Based ◽  
Block Structured
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