Matematický model zaměření tlaku ve spalovací komoře srdcovitého tvaru, nalezenou v přírodě

Mathematical Modelling of a pressure focusing Mechanism in a Heart–shaped Naturally occuring Combustor

conference paper

en

The role of pressure wave focusing in a heart-shaped reaction chamber of Brachinus (Bombardier beetle) was investigated. The defence mechanism of Brachinus was described and numerically modeled. The shape of a naturally occurring reaction chamber was used for practical methane-air combustion to study the advantages of the design. Mathematical modelling of gas combustion shows pressure focusing mechanism given by the combustor shape and its important role in a gas ejection from the vessel. Numerical calculations with stoichiometric methane-air mixture has been carried out showing different features of the design. Fully compressible laminar flow with single step kinetic mechanism was used. The ignition was set-up by rising temperature on the hot walls of the combustor. Results show, that the two phase behavior of the Brachinus defence mechanism cannot be easily reproduced with gaseous combustible mixture. The design of the chamber shows very unique flow-field and pressure wave characteristics. Further research is carried to investigate possible use in gas turbines re-ignition device.

Význam koncentrace tlakových pulsů v srdcovité komoře brouka Brachinae byl zkoumán numericky. Geometrie srdcovité komory obranného mechanismu brouka byla použita pro zvětšený tvar komory na spalování metanu. matematický model prokazuje výrazný vliv koncentrace tlaku na účinnost ejektoru. Vznícení směsi bylo realizováno zvýšením teploty na stěně a pomocí parametrické studie byly určeny hlavní důležité parametry. Další výzkum probíhá s cílem použít design pro vzněcovací zařízení.

The role of pressure wave focusing in a heart-shaped reaction chamber of Brachinus (Bombardier beetle) was investigated. The defence mechanism of Brachinus was described and numerically modeled. The shape of a naturally occurring reaction chamber was used for practical methane-air combustion to study the advantages of the design. Mathematical modelling of gas combustion shows pressure focusing mechanism given by the combustor shape and its important role in a gas ejection from the vessel. Numerical calculations with stoichiometric methane-air mixture has been carried out showing different features of the design. Fully compressible laminar flow with single step kinetic mechanism was used. The ignition was set-up by rising temperature on the hot walls of the combustor. Results show, that the two phase behavior of the Brachinus defence mechanism cannot be easily reproduced with gaseous combustible mixture. The design of the chamber shows very unique flow-field and pressure wave characteristics. Further research is carried to investigate possible use in gas turbines re-ignition device.

spalování, CFD

combustion, CFD, nature design

07.07.2003

Proceedings of the 10th Int. Congress on Sound and vibration

6