CFD consultancy for products that depend on flow
CFD analysis that shows how air, water, oil or gas moves through and around your product, what that costs in pressure and power, and which geometry changes improve it before anything is cut or moulded.
Flow problems rarely show on a drawing. A manifold that looks symmetrical feeds one outlet more than the others. A valve that meets its rated flow on test runs noisy at part opening. A cooling duct loses most of its pressure at one tight bend. By the time a prototype reveals any of this, the tooling is often committed and the fix is a compromise.
More about CFD and fluid dynamics
Computational fluid dynamics (CFD) solves the equations of fluid motion across a digital model of the flow, so velocity, pressure, temperature and turbulence are known at every point in the domain, including places no sensor could reach. The study answers the questions that carry commercial weight: how much pressure the system loses at design flow, whether flow divides as intended, where it separates or recirculates, how much heat it carries away and what forces it puts on the structure.
SixGate™ is the design-to-manufacture process of F-CAD®, a Glasgow engineering company. CFD sits inside its detail design and simulation stage and can also be bought on its own. The engineers who run the flow study design for production too, so each study ends with a recommended geometry and the reasons for choosing it.
Typical work: hydraulic and coolant manifolds, valves, ducting and HVAC components, nozzles and sprays, pumps and fans, filters and separators, vehicle and equipment aerodynamics, and process plant.
What a CFD study answers
What is the pressure drop at design flow?
Total pressure loss through the system, broken down by component, so you can see which bend, filter or valve costs the most and what pump or fan the system needs.
Does the flow divide the way we intended?
Flow rate through each branch, nozzle or channel of a manifold, and how far that split moves as the inlet flow changes.
Where does the flow separate or recirculate?
Dead zones, swirl and reversed flow that waste energy, cause uneven cooling, collect deposits or generate noise, shown in three dimensions.
What loads does the fluid put on the part?
Drag, lift, moments and surface pressure, in a form that can be applied directly as loads in a structural study.
Will the fan or pump reach its operating point?
The system resistance across a range of flows, set against the fan or pump curve, so the delivered flow is predicted rather than assumed.
Which change is worth making?
Design variants compared on the same basis, so the value of a larger radius, a turning vane or a wider port is known before it is made.
What we analyse
Internal flow
Pipes, ducts, manifolds, valves, nozzles, heat exchangers and enclosures, with porous regions for filters, screens and packed beds.
External flow
Air or water moving around vehicles, equipment, buildings and structures, giving drag, lift, surface pressure and wake behaviour.
Pressure drop and flow distribution
Loss coefficients for individual components and for the whole system, and the balance of flow between parallel paths.
Laminar and turbulent flow
Laminar flow in small channels and viscous fluids, and Reynolds-averaged turbulence models for the turbulent flow found in most industrial equipment.
Compressible flow
Gas flows fast enough for density changes to matter, generally above about Mach 0.3, such as vents, relief paths and high-speed jets.
Heat transfer in fluids
Forced and natural convection, and conjugate heat transfer where heat conducts through solid walls into the flow.
Multiphase and free-surface flow
Interfaces between liquid and gas, such as tank filling, sloshing, splashing and drainage.
Rotating parts
Fans, impellers, mixers and rotors, represented with a rotating reference frame or a rotating region of the model.
Before you start
What to send us
- CAD of the flow path, or of the product and its surroundings (STEP or native)
- The fluid, its temperature and any properties that vary, such as viscosity
- Flow rates, inlet pressures or velocities at each operating point
- Outlet conditions, such as discharge to atmosphere or a known back-pressure
- Fan or pump curves, and any filters, screens or valves in the circuit
- The decision the study must support, such as a pressure drop target or flow split tolerance
Do you need the whole system, or just the part?
Only the flow path that affects the answer. A manifold study might stop at its inlet and outlet ports, with the rest of the circuit represented by a pressure or flow condition at each boundary.
How do you decide between laminar and turbulent flow?
The Reynolds number, Re = ρvD/μ, decides it. In a round pipe the flow is usually laminar below about Re = 2,300, and most flows in industrial equipment are turbulent.
Can CFD results feed a structural analysis?
They can. Pressures and temperatures from the flow study are applied to the structural model as loads for stress, deflection or thermal stress studies.
Can you model fluids other than air and water?
Oils, glycol mixtures, fuels and process gases are all common, provided density and viscosity are known over the operating temperature range. Non-Newtonian fluids such as slurries and pastes need a viscosity model fitted to the fluid’s data.
Can you work from early concepts rather than finished CAD?
Often that is the better place to start. A simplified flow model built from key dimensions compares layouts while they are still easy to change.
Tell us where the flow goes wrong
