DU Run Senses

Some Tips for Email Writing

Martin — Thu, 29 Sep 2011 15:22:43 +0800

A subject line should be SMART.

S — Specific
M — Meaningful
A — Appropriate
R — Relevant
T — Thoughtful

10 steps for good business writing:

Remember your ABC (Accurate, Brief, Clear)
Be courteous and considerate
Use appropriate tone
Write naturally and sincerely
Remember the KISS principle (Keep it Short and Simple)
Use modern terminology
Include essential details
Be consistent
Use active not passive voice
Compose CLEAR communications (Clear, Logical, Empathetic, Accurate, Right)

(from

Taylor S. Model Business Letters, Emails & Other Business Documents, 6th ed. Pearson, 2004)

simpleFOAM

Martin — Tue, 10 May 2011 16:30:24 +0800

Now, let’s look at how the simpleFOAM works.

the simpleFOAM.C file:

#include "fvCFD.H"
#include "singlePhaseTransportModel.H" // transport model with viscosity model
#include "RASModel.H" // turbulent model

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

int main(int argc, char *argv[])
{
#   include "setRootCase.H"
#   include "createTime.H"
#   include "createMesh.H"
#   include "createFields.H"
#   include "initContinuityErrs.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

    Info<< "\nStarting time loop\n" << endl;

    while (runTime.loop())
    {
        Info<< "Time = " << runTime.timeName() << nl << endl;

#       include "readSIMPLEControls.H"
#       include "initConvergenceCheck.H"

        p.storePrevIter(); //store the previous value of pressure, necessary for under-relaxation

        // Pressure-velocity SIMPLE corrector
        {
#           include "UEqn.H"
#           include "pEqn.H"
        }

        turbulence->correct();

        runTime.write();

        Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << "  ClockTime = " << runTime.elapsedClockTime() << " s"
            << nl << endl;

#       include "convergenceCheck.H"
    }

    Info<< "End\n" << endl;

    return 0;
}

the UEqn.H file:

// Solve the Momentum equation

    tmp<fvvectormatrix> UEqn  // U equation difinition; fvm means finite volume matrix, implicit
    (
        fvm::div(phi, U)    // divergence of rho.U.U, for incompressible fluid, phi = U
      + turbulence->divDevReff(U)  // turbulent momentum, equivalent
    );

    UEqn().relax(); // under-relax the U equation

    eqnResidual = solve    // solving; fvc means finite volume ..., explicit
    (
        UEqn() == -fvc::grad(p)
    ).initialResidual();

    maxResidual = max(eqnResidual, maxResidual);

the eqnResidual and maxResidual are defined respectively as:

eqnResidual: Initial residual of the equation
maxResidual: Maximum residual of the equations after one solution step

the pEqn.H file:

p.boundaryField().updateCoeffs(); // Update the boundary conditions for p

    volScalarField AU = UEqn().A(); // Calculate the Ap coefficient
    U = UEqn().H()/AU; // calculate U
    UEqn.clear();
    phi = fvc::interpolate(U) & mesh.Sf(); // Calculate the flux
    adjustPhi(phi, U, p);

    // Non-orthogonal pressure corrector loop
    for (int nonOrth=0; nonOrth<=nNonOrthCorr; nonOrth++)
    {
        fvScalarMatrix pEqn  // define the p equation
        (
            fvm::laplacian(1.0/AU, p) == fvc::div(phi)
        );

        pEqn.setReference(pRefCell, pRefValue);

        // Retain the residual from the first iteration
        if (nonOrth == 0)
        {
            eqnResidual = pEqn.solve().initialResidual();
            maxResidual = max(eqnResidual, maxResidual);
        }
        else
        {
            pEqn.solve(); // solve p equation
        }

        if (nonOrth == nNonOrthCorr)
        {
            phi -= pEqn.flux();  // correct the flux
        }
    }

#   include "continuityErrs.H"  // Calculate continuity errors

    // Explicitly relax pressure for momentum corrector
    p.relax();

    // Momentum corrector
    U -= fvc::grad(p)/AU;
    U.correctBoundaryConditions();

References
[1] The SIMPLE algorithm in OpenFOAM. http://openfoamwiki.net/index.php/The_PISO_algorithm_in_OpenFOAM, May 2, 2011

check my work

Martin — Mon, 02 May 2011 17:38:18 +0800

I have been in Hong Kong for 2.5 months.

I passed the probation in two months, generally three-month probation. Although this, I am not satisfied with my performance. Think a lot, do a lot, but gain little.

What’s wrong? What is my expectation about the project?

Must I make a detailed plan? Although I have a plan in my head, it’s not in black and white. I must write it down.

However, I have immersed in the computation. I should make a bird’s-eye view about my project. I must re-organize my thoughts.

The new start

Martin — Sat, 30 Apr 2011 01:50:36 +0800

On Feb 12, I left Chengdu for Hong Kong. This post should be written on that day, but It was delayed. It seems that I should talk about days I live and work in HK. I arrived in HK on Saturday, since I wanted two days for adapting living and climate of HK.

When I arrived at HK airport, Otto, my colleague now, picked up me. Although he forgot to bring a ASM sign, he brought a photo of me. So he recognized me when I went out the arrive-in hall, there is a big screen for finding people who you are picking up. Otto s nice, introduced me some basic information about corporation. He drove me to the corporation dorm, where I could stay up to one month. A Chung, another colleague now, showed me the dorm, which is on 17th floor, and then we were having lunch together, and talk to me about HK and the corporation.

After lunch, A Chung left and I would deal with everything myself. There are lot of road, cross, bridges in HK. Living house is the upper half of the whole building, the lower half is shopping mall. So, it’s easy to lose. I could not find the way to my dorm several times. However, I did it.

I bought a cell phone number for calling and an Octopus card for taking MTR and bus.

It’s noisy in HK, I think. I didn’t sleep well in the first night in HK. Too noise went into my ears. It’s better in the second night.

It was Monday, the first day I joined the corporation formally. A Chung picked me up to ASM. Then a colleague, I forget her name, introduced me the corporation rules, and handed me two sets of uniforms. After that, I met my boss. He introduced the R&D department and my jobs, then introduced me colleagues.

After lunch with Chris, a French colleague, I began to work. Yes, a new starting point.

A list of reference paper of verification and validation in CFD

Martin — Sun, 27 Feb 2011 01:06:20 +0800

[1] MacCormack R W. A perspective on a quarter century of CFD research.AIAA-93-3291-CP,1993

[2] Roache P J, Chia K, White F. Editorial policy statement on the control of numerical accuracy.Journal of Fluids Engineering,1986,108(1):2

[3] AIAA. Editorial policy statement on numerical accuracy and experimental uncertainty.AIAA Journal,1994,32(1):3

[4] Editorial Board. Journal of heat transfer editorial policy statement on numerical accuracy.Journal of Heat Transfer,1994,116:797～798

[5] AIAA. Guide for the verification and validation of computational fluid dynamics simulations.AIAA G-077-1998,1998

[6] Metha U B. Guide to credible computational fluid dynamics simulations.AIAA-95-2225,1995

[7] Roache P J. Verification of codes and calculations.AIAA Journal,1998,36(5):696～702

[8] Schlesinger S. Terminology for model credibility.Simulation,1979,32(3):103～104

[9] Roache P J. Code verification by the method of manufactured solutions.ASME Journal of Fluids Engineering,2002,114(1):4～10

[10] Roache P J. Need for control of numerical accuracy.Journal of Spacecraft and Rockets,1990,27(2):98～102

[11] Rizzi J V. Toward establishing credibility in computational fluid dynamics simulations.AIAA Journal,1998,36(5):668～675

[12] Oberkampf W L,Trucano T G. Validation methodology in computational fluid dynamics.AIAA-2000-2549,2000

[13] Oberkampf W L,Trucano T G. Verification and validation in computational fluid dynamics.SAND 2002-0529,2002

[14] Gnoffo P. CFD validation studies for hypersonic flow prediction.AIAA-2001-1025,2001

[15] Stern F,Wilson R,Coleman H,et al. verification and validation of CFD simulations[R]. Iowa Institute of Hydraulic Research, The University of Iowa, Iowa city,IIHR report No.4.7,1999.

[16] Deng Xiaogang, Zong Wengang, Zhang Laiping et al. verifaication and validation in computational fluid dynamics[J]. Advances in Mechanics,2007,37(2):279-288.

[17] Zhu Dexiang, Zhang Zhirong, Wu Chensheng et al. Uncertainty analysis in ship CFD and the primary application of ITTC procedures[J].Journal of Hydrodynamics, 2007,22(3):363-370.

[18] Stern F, Wilson R, Coleman H et al. Comprehensive Approach to verification and validation of CFD simulation – Part 1:Methodology and Procedures[J]. Journal of Fluids Engineering.2001:123(4),793-802.

[19] Stern F, Wilson R, Coleman H et al. Comprehensive Approach to verification and validation of CFD simulation – Part 2: Application for RANS Simulation of Cargo/Container Ship [J]. Journal of Fluids Engineering.2001:123(4),803-810.

[20] Stern F, Wilson R, Coleman H et al. Verification and validation for RANS simulation of a naval combatant[C]．Proc．of Go thenburg 2000一A Workshop on Numerical Ship Hydrod ynamics．Chalmers U．of Technology，Go thenburg，Sweden．

[21] LARS Larsson，FREDERICK Stern，VOLKER Bertram．Proceedings of Gothenburg 2000一A W orkshop ofNumerical Ship Hydrodynamics[C]．Gothenburg，Sweden，2000．

[22] John W.Chew, Nick Hills, Konstantin N. Vlokv. verification and validation of CFD results for turbomachinery applications[C]Venice Italy 2008

[23] Struart E. Rogers and Karlin Roth. CFD validation of High-lift flows with significant wind tunnel effects[C] AIAA2000-4218 Denver ,Colorado

[24] P. J. Roache. Verification and Validation in Computational Science and Engineering. Hermosa Publishers,Albuquerque, NM, 1998.

[25] Clarence O. E. Burg, Chunhua Sheng, James C. Newman, III, Wesley Brewer. VERIFICATION AND VALIDATION OF FORCES GENERATED BY AN UNSTRUCTURED FLOWSOLVER

[26] M.Hemsch, J.Grubb, W.Krieger, D.Cler. Langley Wind Turnel Data Quality Assurance –check Standard results[C].AIAA2000-2201 Denver ,Colorado

[27] John C. Vassber,Antony Jameson. In Pursuit of Grid Convergence,Part I: Two-Dimensional Euler Solutions[C].AIAA 2009-4114 San Antonio,Texas

[28] Eca L, Hoekestra. on the application of verification procedures in computational fluid dynamics” 2nd MARNET workshop

[29] Metha U B. credible computational fluid dynamics simulations[J]. AIAA 36 665-667

[30] Coleman H W, Stern F. Uncertenies in CFD validation [J]. Journal of Fluids Engineering.1997:119(4),795-803

[31] Author`s closure[J]. Journal of Fluids Engineering.1998:120(3), 635-636

[32] Rood E P. validation stragtegy for RANS computational ship hydrodynamics[C],2nd international conference on hydrodynamics.Hongkong 1996

[33] Oberkampf W L,Trucano T G. validation Methodology in computational fluid dynamics[C].AIAA fluids 2000-2549,Denver CO.

[34] Coleman H W, Stern F, Mascio A, et al. The problem with oscillatrory Behavior in Grid convergency studies[J]. Journal of Fluids Engineering.2001:123(2),438-439

[36] Ebert M P, Gorski J. A validation and verification Procedure for Computational fluid Dynamics Solutions” NSWCCD-50-TR-2001/0006

(Forwarded from http://waynepump.spaces.live.com/blog/cns!DA5127EECE004EE9!514.entry )

Because it’s written on microsoft live space, I am afraid it’s missing. So I copied the post here for a reference. Other references please read http://www.grc.nasa.gov/WWW/wind/valid/tutorial/bibliog.html

Happy Chinese New Year

Martin — Wed, 02 Feb 2011 21:44:56 +0800

Kung Hei Fat Choy! It’s Chinese New Year’s Eve. Chinese New Year’s atmosphere is full of everywhere, because red is everywhere, which means you will have a happy new year. As Chinese Tradition, it’s the year of the Rabbit.

Happy Chinese New Year!

New Year’s Resolution in 2011

Martin — Fri, 28 Jan 2011 13:39:10 +0800

It’s 2011. I have turned to 30 years old, but I have not start my job. However, A Hong Kong based company provides me a full-time job, and I will begin working after Chinese New Year. It’s time to make a plan for a New Year. Although I don’t know what the exact work to do as my job, I’d like to make a general plan.

Keep my mind clear, my body healthy;
Keep a good spirit facing any job;
Keep a good teamwork;
Keep learning;
Contact my family frequently;
Save 1/3 of my salary/income.

2010 in Review

Martin — Fri, 31 Dec 2010 23:01:01 +0800

In 2010, I have done several important things in my life.

Finished my PhD thesis, and passed the oral defense.
Got the first job provided by a Hong Kong company.

The significant things happened to me: My father passed away in 2010. My parents had been living for more than 30 years. My mother is living alone in my hometown. That means she should take care of herself and learn modern life, new skills.