Dacolt provides high-quality CFD consultancy services
Global concerns on fuel efficiency and pollutant emissions require more predictive CFD simulations for further improvement of combustion apparatus performance. Dacolt combines expertise with state-of-the-art simulation tools for providing high-quality CFD analyses.
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 PSR+PDF 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.
Advanced, flamelet-based combustion models like RIF , FGM , FPI , ECFM-3Z  or ECFM-CLEH  which have appeared in recent literature have proven to yield substantial improvement as compared to default models available in most CFD software packages. Dacolt has implemented its own advanced combustion model in ANSYS® FLUENT®, called Dacolt PSR+PDF. This model applies to the following problem types:
- Steady-state: non-premixed and flameless (or MILD) burners
- Unsteady: Diesel engines, HCCI, PCCI, SI engines knock
Dacolt PSR+PDF has the following features:
- Progress variable / mixture fraction approach
- Turbulence / chemistry interaction based on a presumed PDF
- Complex chemistry model: Perfectly Stirred (or homogeneous) Reactor
- Use of Tabkin® to create the required CFD look-up tables, based on detailed chemical kinetics
With Dacolt PSR+PDF substantial improvements in CFD results can be achieved as detailed chemical kinetics and adquate turbulence - chemistry interaction are both accounted for.
When conducting CFD studies for industrial customers, Dacolt adopts the preferred CFD package of the customer. If the customer has no preference, Dacolt uses ANSYS FLUENT or ICON FOAMpro. Dacolt also has experience in CFD modelling with various other CFD packages:
- Open Source software: Kiva, Code_Saturne, OPENFOAM®
- Proprietary software: AVL FIRE and Star-CD from CD-adapco
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.
- N. Peters, Turbulent Combustion. Cambridge University Press, 2000.
- J.A. van Oijen, F.A. Lammers, L.P.H. de Goey, Combust. Flame 127(3) (2001) 2124–2134.
- O. Gicquel, N. Darabiha, D. Thevenin, Proc. Combust. Inst. 28 (2000) 1901–1908.
- O. Colin et al., Oil Gas Sci. Technol. 58 (1) (2003) 47–62.
- G. Subramanian et al., SAE Technical Paper Series 2007-01-0154.