Benefits of CFD
CFD offers a great potential in reducing development time and cost of combustion equipment. Typical CFD studies may involve:
- Design adaptation of an industrial burner for lower manufacturing costs
- Parametric investigation of geometrical features on flame length
- Investigation of fluctuations in natural gas composition for gas turbine combustion stability
- Optimisation of Diesel engine bowl shape for pollutant emissions
- Benchmark between two or more combustion models or CFD codes
Dacolt has realised several combustion CFD studies for a wide range of applications, from compact domestic burners of ATAG to large-scale sulpher reduction burners of Duiker.
Dacolt FGM combustion model
The key to obtaining meaningful results from CFD for combustion applications is the use an appropriate combustion model. The choice of a particular model should be based on the capability of the model to capture the physics of the problem considered. For example, the characteristics of the problem may involve a lifted flame, as illustrated by the image above. If the turbulent combustion model does not contain the physics capturing the flame lift-off, it will certainly not have any predictive capability for pollutant emissions. In other words, the basic physics must be right.
Dacolt has implemented its own advanced combustion model (Dacolt FGM) in leading CFD codes. Dacolt FGM has the following features:
- Progress variable / mixture fraction approach
- Turbulence / chemistry interaction based on a presumed PDF
- Use of Tabkin® to create the required CFD look-up tables, based on detailed chemical kinetics
With Dacolt FGM substantial improvements in CFD results can be achieved as detailed chemical kinetics and adquate turbulence - chemistry interaction are both accounted for. And most importantly, CFD runtimes are very affordable in an engineering project context.
When conducting CFD studies for industrial customers, Dacolt adopts the preferred CFD package of the customer. Dacolt has experience in CFD modelling with the following CFD packages:
- Industrial burners and gas turbines: Ansys Fluent and OpenFOAM
- Internal combustion engines: OpenFOAM, Converge, AVL FIRE, Ansys Fluent and Star-CD
Dacolt has extensive experience in automating parts of the CFD workflow, using advanced scripting methods for parametric geometry definition, mesh generation, simulation set-up and execution and post-processing. Automation is often required when performing parametric analyses or optimisation studies.