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 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, regime, flow features → model, wall treatment, y+ band, checks
Open the selector →
y+ = uτy / 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 · Pr · Ma · Fr · We · Bi
Calculator
Dimensionless numbers
27 numbers for flow, heat transfer and particles, and what each one means for your set-up.
Fluid properties, U, L → Re, Pr, Ma, Fr, Bi, We and more
Open calculator →
Re = ρUL / μ
Calculator
Reynolds number calculator
Find the Reynolds number and the flow regime of a pipe or duct, a flat plate, a cylinder or a sphere.
Shape, size, flow, fluid → Re, regime, transition point
Open calculator →
C = |u|Δt / Δx
Calculator
Courant number calculator
Find the Courant number of your time step and cell, or the time step for a target C, with the limits for LES, free surface and sound.
Cell, speed, time step, fluid → C, Δt, the limit that sets it
Open calculator →
Δp = f (L/D) ρV²/2
Calculator
Pipe pressure drop calculator
Pressure drop and head loss of a pipe by Darcy–Weisbach, with the friction factor on a live Moody chart.
Fluid, pipe, roughness, flow → Δp, head loss, f, Re
Open calculator →
Verify results and plan studies
Quantify mesh uncertainty and size a design study before you spend the compute.
GCI = Fs|ε| / (rp − 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 = Lk
Calculator
DOE calculator
Choose a design for your goal and see how many simulation runs it needs.
Goal, variables, run time → design, runs, wall time, points
Open calculator →
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 →
CD = 2FD / (ρU2A)
Reference
Drag coefficients
Look up CD for common 2D and 3D shapes.
Covers: shapes, flow dependence, simulation set-up tips
Read reference →
Structures and strength
Check a beam or a stress state by hand, and see how topology optimisation decides where material goes.
n = Sy / σvM
Calculator
Von Mises stress calculator
Von Mises stress, principal stresses and the safety factor against yield.
3D tensor, plane stress or principal stresses → σvM, Tresca, n
Open calculator →
δ = PL3 / 48EI
Calculator
Beam calculator
Reactions, bending moment, deflection and stress for simply supported, cantilever and fixed beams.
Supports, span, loads and section → R, M, δ, σ, n
Open calculator →
σt = σe(1 + εe)
Calculator
Stress–strain curve calculator
Convert engineering to true stress up to necking and get the plastic strain table for FE input.
E, yield, Rm, Agt or a test record → σt, εp, FE deck
Open calculator →
E = xp E0
Guide
Topology optimisation, explained
See how the solver finds where material is needed, on a beam we computed ourselves.
Covers: the MBB beam, SIMP, filters, manufacturing constraints
Open guide →
Basics and downloads
Background reading and starting files for Simcenter STAR-CCM+.
∂ρ/∂t + ∇·(ρu) = 0
Guide
Computational fluid dynamics (CFD), explained
What CFD is, how a simulation runs from geometry to result, and where it is used.
Covers: the equations, meshing, turbulence models, checking a result, a worked example
Open guide →
aPφP = Σ anbφnb + b
Guide
Finite volume method (FVM), explained
How a CFD code turns the flow equations into a balance for every cell.
Covers: face fluxes, upwind and central schemes, cell shapes, a 1D example to run
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, digital twin simulation, finite element analysis, fluid–structure interaction and topology optimisation.
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.
Can Volupe help me set this up in Simcenter STAR-CCM+?
Yes. Customers get support from our engineers, and we run Simcenter STAR-CCM+ training courses. If you are not using Simcenter STAR-CCM+ yet, ask us about a trial, or send us a technical question.
Can I suggest a new calculator or report an error?
Yes, please do. Use the form below and choose “Technical question”.
Talk to an engineer in your region
Every Volupe business developer holds an engineering degree. Find your regional contact below, or send us a message.
Ask us about CFD Handbook
Use this form for licence quotes, demos, training and technical questions.
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- A reply within one day.
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After purchase: support from Volupe simulation engineers.