CFD Handbook

Free calculators and reference pages for CFD engineers: mesh sizing, turbulence set-up, verification and heat transfer, maintained by Volupe's application engineers.

Set up and mesh Verify and plan Heat transfer and drag Basics and downloads

11 tools and references · Free, no sign-up · Last reviewed October 2026

Set up and mesh a simulation

In the order you usually need them for a new case.

k–ω SST · k–ε · S–A

Interactive guide

Turbulence model selector

Pick a turbulence model and wall treatment for your case in Simcenter STAR-CCM+.

Application, flow features → model, y+ target, prism layers, Java macro

Open the selector →

y⁺ = u_τy / ν

Calculator

y+ calculator

Size the first cell for a target y+, then the prism layer stack.

U, ρ, μ, L, y+ → first cell height, δ, prism layer settings

Open calculator →

k = ³⁄₂ (U I)²

Calculator

Turbulence boundary conditions calculator

Turn turbulence intensity into inlet k, ε, ω and ν̃.

U, ν, intensity + length scale or viscosity ratio → k, ε, ω, ν̃

Open calculator →

Re = ρUL / μ

Calculator

Dimensionless numbers

Check the flow regime before you pick models and mesh.

Fluid properties, U, L → Re, Pr, Ma, Fr, Bi, We and more

Open calculator →

Verify results and plan studies

Quantify mesh uncertainty and size a design study before you spend the compute.

GCI = F_s|ε| / (r^p − 1)

Calculator

Grid Convergence Index (GCI) calculator

Quantify mesh uncertainty from a three-grid refinement study.

3 meshes + results → observed order, GCI, extrapolated value

Open calculator →

N = m^k

Planner

DOE calculator

Estimate how many simulation runs a design study needs.

Variables, levels, run time → runs and time per method

Open planner →

Heat transfer and drag

Correlations and reference values to check a set-up by hand.

h = Nu k / L

Calculator

Nusselt number calculator

Estimate convective heat transfer from standard correlations.

Geometry, fluid properties, flow → Nu, h

Open calculator →

Nu = C Raⁿ

Reference

Heat transfer coefficient correlations

Look up convective heat transfer correlations for common geometries.

Covers: natural and forced convection on plates and cylinders

Read reference →

C_D = 2F_D / (ρU²A)

Reference

Drag coefficients

Look up C_D for common 2D and 3D shapes.

Covers: shapes, flow dependence, simulation set-up tips

Read reference →

Basics and downloads

Background reading and starting files for Simcenter STAR-CCM+.

∂ρ/∂t + ∇·(ρu) = 0

Introduction

Basic CFD concepts

Get started with CFD through short explanations and curated video lessons.

Covers: governing equations, workflow, turbulence modelling, meshing

Open guide →

5 templates · .sim

Downloads

Templates for Simcenter

Start from ready-made Simcenter STAR-CCM+ template files.

Includes: get-started (v2306), wire-grid porous baffles, LMP, EMP and DEM multiphase

See downloads →

Questions about the CFD Handbook

Volupe's application engineers build and maintain the CFD Handbook from the questions we answer in support every week. We are adding the method, sources and a named reviewer to every tool page, starting with the y+ calculator. For the wider picture beyond CFD, read our guides to CAE simulation and digital twin simulation.

Your contact for the CFD Handbook

Christoffer Johansson

Senior Application Specialist, M.Sc.

Found an error or missing a tool? We reply within one day.

Ask a technical question →

Are the calculators free to use?

Yes. There is no sign-up, and the calculations run in your browser, not on our servers. Our normal site analytics apply; see our privacy policy.

Do the tools only work with Simcenter STAR-CCM+?

No. The physics is the same in any CFD code. Where a result maps to a solver setting, we name the matching Simcenter STAR-CCM+ setting.

Who builds and checks the calculators?

Volupe's application engineers, who support Simcenter users every day. We are adding the method, assumptions, sources and a named reviewer to each tool page.