课程名称：高等计算流体力学 - sjtu ·...

课程名称：高等计算流体力学

Advanced Computational Fluid Dynamics

课程代码：NA6024

主讲人：万德成 [email protected]

助教：陈翔 [email protected]

Shanghai Jiao Tong University 课程安排

学时数： 48 = 30 (讲课) + 18 (报告交流)

学分：3 学分

考查方式：报告交流，编程计算，总结报告

Shanghai Jiao Tong University

C. Hirsch, Numerical Computation of Internal and External Flows-Fundamentals of Numerical Discretization, John Wiley & Sons, Vol I, 1995C. Hirsch, Numerical Computation of Internal and External Flows-Computational Methods for Inviscid and Viscous Flows, John Wiley & Sons, Vol II, 1995 Heike Emmerich, Britta Nestler, Michael Schreckenberg, Interface and Transport Dynamics-Computational Modelling, Springer, 2003

参考书


P.J. Roach, Computational Fluid Dynamics, Hermosa Press, 1976.P. Wesseling, Principles of Computational Fluid Dynamics. Springer, 2001.S. Turek, Efficient Solvers for Incompressible Flow Problems: An Algorithmic and Computational Approach, LNCSE 6, Springer, 1999.C. Cuvelier, A. Segal and A. A. van Steenhoven, Finite Element Methods and Navier-Stokes Equations. Kluwer, 1986.

参考书


1. 吴子牛，计算流体力学基本原理，科学出版社，2002年

2. 任玉新，陈海昕，计算流体力学基础，清华大学出版社，2006年

3. 张涵信，沈孟育，计算流体力学：差分方法的原理和应用，国防工业出版社，2003年

参考书


1. 概述：背景，概念，思路2. 网格：网格类型，结构化网格，非结构化网格，分块网格，conforming网格

3. 网格生成方法：PDE, Delaunay方法4. 方程离散理论和方法：差分法、有限体积法，有限元法

5. 流体力学方程规范法和简化处理：Euler，对流，扩散，Laplace，N-S，湍流模型

6. 纯对流方程求解：FCT，迎风格式，TVD，ROE方法，Streamline Diffusion方法

7. 高效求解方法：多重网格法，GMRES-LU-SGS方法, Space-Marching方法

课程内容


8. 不可压流场求解：投影法，SIMPLE，

人工可压缩法

9. 自由面求解方法：VOF，Level set方法

10. 网格自适应方法

11. 时间步求解方法与时间自适应方法

12. Overset Grid方法

13.无网格方法：SPH, MPS

14. GPU方法

15. 并行计算


Introduction

Shanghai Jiao Tong University What is CFDFluid (gas and liquid) flows are governed by partial differential equations which represent conservation laws for the mass, momentum, and energy.Computational Fluid Dynamics (CFD) is the art of replacing such PDE systems by a set of algebraic equations which can be solved using digital computers.CFD is a branch of applied mathematics which deals with the analysis and prediction of flow phenomena by means of detailed numerical simulations.


What is CFD

CFD provides a qualitative (and sometimes even quantitative) prediction of fluid flows by means of• mathematical modeling (partial differential

equations)• numerical methods (discretization and solution

techniques)• software tools (solvers, pre- and postprocessing

utilities)

CFD enables scientists and engineers to perform ‘numerical experiments’ (i.e. computer simulations) in a ‘virtual flow laboratory’


• Ship Hull Optimization

What is CFD


• High Speed Vessels– High Froude number– Catamarans, trimarans, slender monohulls

What is CFD


• Propulsor, Rudder, Appendage, Hull Interaction

To develop and validate the capability to make detailed, accurate, efficient and reliable predictions of the flow around ship hulls with propellers at full size.

What is CFD


Wind turbine installed offshore can be much larger than those installed on land

Because of harsh marine environment, offshore wind turbines must be more reliable

Wind turbines installed in deeper waters farther from shore will require new foundation and platform technologies

• Ocean Wind Turbine

What is CFD


Rotor-Floater-Mooring coupled

dynamics

What is CFD


What is CFD

Shanghai Jiao Tong University What is CFD

Shanghai Jiao Tong University What is CFDNumerical simulations of fluid flow (will) enable• architects to design comfortable and safe living environments• designers of vehicles to improve the aerodynamic characteristics• chemical engineers to maximize the yield from their equipment• petroleum engineers to devise optimal oil recovery strategies• surgeons to cure arterial diseases (computational hemodynamics)• meteorologists to forecast the weather and warn of natural disasters• safety experts to reduce health risks from radiation and other hazards• military organizations to develop weapons and estimate the damage• designers and optimization of ship hull and marine structures


What is CFD

Real experiment

Shanghai Jiao Tong University What is CFD

CFD simulation


What is CFD

Shanghai Jiao Tong UniversityIntroduction


Breaking waves

Spilling waves

“Rooster” tail

Highly turbulentflow

Splashing drops

Introduction


CFD examples for Ship and Ocean Engineering Flows


The surface ship flow and other related ocean engineering flow problem are related to: Shape of ship and ocean structures：complex geometry Free surface flows：moving interface Nonlinear problem: Nonlinear governing equations,

Fully nonlinear boundary conditionapplied on free surface

Incompressible viscous flows: Viscous flows with high Re, decoupled pressure field and velocity field

6 degree of freedom: moving boundary

Introduction


CFD techniques have to support:• Time domain simulation;

• Simulation in bounded domain;

• Simulation of free surface waves dominated by gravity;

• Fully nonlinear boundary condition applied on

both free surface and body surface;

• Physical (ocean) wave generation and absorption;

• Viscous flows with high Re;

• Calculation of 6DOF motion of body in fluid.

Introduction


University of Tokyo, H. Myiata, 1980s- FDM & MAC TUMMAC-IV (1980s)- FVM & density-function WISDAM-V (1990s)- WISDAM-V + OVERSET WISDAM-X (2003)

National Maritime Research Institute (NMRI)- Takanori Hino SURF (1980s)- Unstructured grid, Level-set, Artificial compressibility

Kyushu University, C. Hu, et al. (2010)Seoul Nation University, Y. Kim, et al. (2011)- CIP, Cartesian grids

Introduction


Germany, R. Azcueta (2002, 2004)- Based on COMETEcole Central de Nantes (ECN)- Wackers & Deng, et al. (2011)- ISIS-CFD, Adaptive grid refinementLars Larsson, Chalmers University of Technology

- SHIPFLOW, Potential+Boundary Layer+RANS

INSEAN, R. Broglia (2006, 2009, 2011)Texas A&M University, H.C. Chen (2010)George Manson， C. Yang （2006）- FEFLO: FEM, VOF, ALE, Unstructured Mesh

Introduction


The University of IOWA- CFDSHIP-Iowa (1990s ~ Now)- F. Stern- R.V. Wilson, E. Paterson- P.M. Carrica, T. Xing- R. Noack (Penn State)• FDM, level-set (surface tracking), overset

In China, so far most NMB are developed based on commercial software, like FLUENT, CFX.

Introduction


PotentialFlows Model

Viscous Flows Model

Boundary Layer

RANS

LES

DNS

Panel method, BEMWave pattern

Global cal.

Nonlinear flows

Interaction Local cal.

MACVOF

Level setMeshless

Introduction


Potential flow RANS solution

Good prediction of the Kelvin wake!


Potential flow RANS solution

Wave heights aft of the stern slightlyOver-predicted and broader wave peak.

Good prediction of the wave heights and topology in the stern region.


• Inviscid methods still heavily used– Free surface Panel Methods (linear, non-

linear)

• RANS calculations– Large amount of hull forms– Increasingly sophisticated with actual

geometry: appendages, bilge keels, shafts, struts, propulsors


CFD Softwares:

commercial Fluent, CFX, COMETShipFlow

noncommercial FEFLO，CFDSHIP

Open sources tools OpenFoam, FreeShip, Gerris, DUNS

Introduction

课程名称：高等计算流体力学 - sjtu ·...

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