Research on Combustion Chambers – First trial on PLIF system

CFD reaction zone

Research on Combustion Chambers – First trial on PLIF system

Sponsored by the Ministry of Industry and Trade, a research project on combustors is under way at VZLU´s Engine Division within a Ministry program FT-TA5/073. The project regards combustors with premixing delivery tubes, C(P)DT, to cover both theoretical and experimental research into annular combustion chambers for small turbine engines. Design and optimization techniques employ modern CFD methods (Computational Fluid Dynamics) to study the reaction flow. New mathematical models of gas fuel combustion have been devised allowing chemical reaction kinetics. Currently, mathematical models for liquid fuel combustion are being developed.

Reaction flows are without exaggeration the most sophisticated case from the point of view of numerical simulation, making great demands on the computational power and quality of mathematical models. The present state of the art and availability of the computational technology make it possible to use ever more complex and precise models, which are close to the real world. Nevertheless it is still impossible now and in the near future to perform a realistic simulation of burning without experimental verification and “tuning” of a numerical model. For this reason VZLU together with PBS Velká Bíteš have jointly built up an experimental system to study the burning process in the combustor segments under atmospheric and elevated pressures at air temperatures up to 460K. The experimental chamber has made it possible to verify basic thermodynamic parameters and take the very first 2D measurements in the Czech Republic of the distribution of OH radical concentration by the PLIF method (Planar Laser Induced Fluorescence) carried out by Laboratory of Fluid Mechanics at Czech Technical University ČVUT. This method employs the principle of capture of spontaneous radiation of excited molecules by means of a digital camera and allows a very selective determination of the molar concentration in a given control volume. The OH PLIF results provide a qualitative picture of the flame reaction zone for validation of results from numerical models.

Our goal is to help Czech and foreign partners find quick and effective solutions to problems associated with the design and optimization of combustion facilities. To achieve this goal, we use both classic and latest numerical and experimental methods.