Categories - CFD

18 posts in total

CFD | Direct Numerical Simulation, DNS

在計算流體力學（CFD）的最高境界——直接數值模擬 (Direct Numerical Simulation, DNS) 中，耗散率（Dissipation Rate）是衡量能量如何從大尺度渦流傳遞至微小尺度並最終轉化為熱能的核心物理量。 Direct Numerical Simulation 1. Incompressible Flow 物理表達式 (不可壓縮流)在不可壓縮流（Incompres

2026-02-26

CFD

#HPC #OpenFOAM #LES #RANS #URANS #DES #DNS #Dissipation Rate

CFD | Video

RANS, URANS, and DES Turbulence Modeling on NACA 0012 Airfoil NACA 0012 Airfoil CFD Simulation in TCAE | RANS, URANS, DES & LES @ 40 FPS NACA 0012 CFD Simulation in TCAE | RANS, URANS, DE

2026-02-05

CFD

#HPC #OpenFOAM #LES #Youtube #RANS #URANS #DES

CFD | Euler equations | zero viscosity | Turbulence

Non-Linear Term In Computational Fluid Dynamics (CFD), the transition from the base Navier-Stokes equations to turbulence modeling involves understanding how nonlinearity behaves and how averaging cre

2026-01-06

CFD

#OpenFOAM #Euler equations #viscosity #Turbulence

CFD | OpenFOAM | gcc : error: unrecognized command line option ‘--showme:link’; did you mean ‘--force-link’?

Error Error 1 gcc: error: unrecognized command line option ‘--showme:link’; did you mean ‘--force-link’? The error message you are seeing, gcc: error: unrecognized command line option ‘--showme:link

2026-01-02

CFD

#HPC #OpenFOAM #MPI #error #intelmpi #openmpi

CFD | Turbulence model activation (use or not use)

Question: When should we exclude the turbulence model? In Computational Fluid Dynamics (CFD), the decision to omit a turbulence model is usually driven by the physics of the flow or the resolution of

2025-12-19

CFD

#HPC #OpenFOAM #turbulence model #SST k-omega

CFD | Flat Plate

1. Why the Flat Plate Case is Important in CFD The flat plate boundary layer problem is a cornerstone in fluid dynamics, and its study using CFD is critical for several reasons: Foundation for Bound

2025-12-09

CFD

#HPC #OpenFOAM #Blasius Solution

CFD | OpenFOAM | fluentMeshToFoam .msh to openfoam

Issue 一个可压缩超音速OpeNFOAM算例，想找个fluent大佬来设置一个粘度： 0 湍流模型：无二维算例，所有壁面都可以为滑移，或者零梯度边界进口边界：静压：1e5、温度：400K、速度：1000m/s 没有其他进口；右边是出口稳态网格数量：10000个 OpenFOAM计算大约3秒算完。最大压力 810000。想看一下Fluent的最大压力多

2025-01-15

CFD

#HPC #OpenFOAM #fluent #mesh

CFD | Boussinesq approximation (buoyancy)

Boussinesq approximation (buoyancy) In fluid dynamics, the Boussinesq approximation is used in the field of buoyancy-driven flow (also known as natural convection). It ignores density differences exce

2025-01-03

CFD

#HPC #OpenFOAM

CFD | DNS

DNS A direct numerical simulation (DNS) is a simulation in computational fluid dynamics (CFD) in which the Navier–Stokes equations are numerically solved without any turbulence model. This means that

2024-12-23

CFD

#HPC #OpenFOAM

CFD | Wall Function

Why using wall functions approach? Nowadays turbulence models are heavily used when doing CFD simulations. However, some mature turbulence models such as $ k-$ are only valid in the area of turbulence

2024-12-18

CFD

#HPC #OpenFOAM

CFD | RANS vs. URANS vs. LES

Characteristics of turbulence One characteristic of turbulent flows is their irregularity (or randomness). A fully deterministic approach to characterize turbulent flows is very difficult. Turbulent f

2024-12-18

CFD

#HPC #OpenFOAM

CFD | OpenFOAM | STL file | 網格生成

OpenFOAM三維網格生成器 snappyHexMesh（SHM）是OpenFOAM軟體的三維結構化網格生成模組，功能比較強大，設定靈活，表面處理貼合功能非常強健並且可以並行運算。 SHM能夠透過使用者自訂參數（如細化參數castellatedMeshControls、切合參數snapControls等）對預先載入的幾何體檔案（通常為'.stl'檔案）自動實現三維網格生成、加密(castella

2024-12-05

CFD

#HPC #OpenFOAM

CFD | OpenFOAM | In parallel

Running applications in parallel Both domain decomposition and reconstructionprocesses can only be done on a singlecore. This section describes how to run OpenFOAM in parallel

2024-12-04

CFD

#HPC #OpenFOAM

CFD | OpenFOAM | Notes/Blogs

Notes/Blogs 筆記/部落格列表 CFD study and method development for air intake systems using OpenFOAM 2020 | GIOVANNI CALZOLARI KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ENGINEERING SCIENCES Urban Wind Flo

2024-12-04

CFD

#HPC #OpenFOAM

CFD | OpenFOAM | Allrun

Allrun All OpenFOAM tutorials have Allrun and Allclean scripts which call some mysterious RunFunctions from even more mysterious sources. Source OpenFOAM first, source /home/wpsze/openfoa

2024-12-03

CFD

#HPC #OpenFOAM

CFD | SIMPLE 算法

不可壓縮 Navier-Stokes 方程對於不可壓縮Navier-Stokes方程，可以表示為：動量方程： \[ \rho \frac{\partial \mathbf{u}}{\partial t} + \rho (\mathbf{u} \cdot \nabla) \mathbf{u} = -\nabla p + \mu \nabla^2 \mathbf{u} + \mathbf{f} \

2024-11-26

CFD

#HPC #OpenFOAM

CFD | OpenFOAM Installation

OpenFOAM OpenFOAM是一個CFD軟體。它包括一系列應用程序，這些應用程式在CFD中執行一系列任務。應用程式主要分為兩類：link 求解器，用於執行CFD計算；以及實現上述任務的其他程序；在OpenFOAM-11之前，每個流動類型都需要呼叫特定的求解器。由於流動類型非常多，OpenFOAM層包含了近100個解算器。像simpleFoam和pimpleFoam這樣的求解器自上世紀

2024-11-20

CFD

#HPC #OpenFOAM

CFD | Incompressible and Compressible

Governing Equations The equations that govern the fluid flow are based on the conservation laws of a fluid’s physical properties. The basic equations are the three laws of conservation1: Conservation

2024-11-15

CFD