Design And Numerical Prediction Research Of Combustor Experiment Rig

The structure design and performance improvement of the combustion chamber areinseparable from relevant test and experimental verification．In this dissertation，a set of testrig for combustion chamber is designed，which can be used to analyze the flow field structureof the nozzle and swirl. It also can be used to make the process of the liquid fuel combustionvisible to us．The result provides guidance for the combustor structure design and thecomponent performance optimization.In this dissertation, pro/E is used to design the structure of the experiment rig. Thedesign of the experiment rig refers to the national standard of the engineering pressure vessel.The arrangement of the optical observation windows is deliberated, and a set of mechanicaladjustment device is added to broaden the scope of observations so that the complexphenomena such as combustion and atomization can be studied clearly. Both the rich burningpremixed and the lean burning premixed methods are used in the process of the experimentrig design inside the atomization tube. The structure can be improved by using numericalcalculation method. A variety of structures are compared in the fuel-rich project. Thedifferences between n-heptane and kerosene are taken into account. Kerosene is studied in thelean burn project. The design of the swirl at the head of flame tube is improved carefully.Realizable k εturbulence model and EBU-Arrhenius combustion model are adopted in thecalculative process of the internal combustion in the test device. One order upwind scheme isused to discrete the equations. SIMPLE algorithm method is applied to solve the equations.Numerical results show that optimal distribution of both temperature field and reactionzone at the head of the flame tube can be achieved using the fuel-rich project and method ofcoflowing jets with large velocity differences. The straight ring can be arranged at the ringinstallation which introduces the air into the tube. The reaction zone can be shortened andablation of the tube wall can be avoided by increasing the flow rate coming from the ring andstrengthening the mixing between air and fuel. Flashback maybe occurs due to the fact thatthe velocity of the mixture gas is slow in the programs of the fuel-rich premixed. N-heptane issimilar to kerosene on the calorific value. The temperature field is similar if the simplifiedone-step reaction mechanism is utilized in the calculation process, n-heptane can be used to estimate the distribution of temperature of kerosene in advance. However, kerosene should beused to investigate the atomization and evaporation for the physical properties between thetwo kinds of fuel is quite different.The occurrence of the flashback can be avoided by using lean burning premixed projectbecause the fuel residence time is shortened by increasing the airflow speed. The appropriatedesign of the flame stabilization should be used in this condition. The swirler with a hole inthe central axis can be used to effectively prevent the high-temperature reaction productwhich comes from the back of the bluff body form wall ablation and the reaction length in thecombustor can be strengthened. Jet rigidity in the central axis plays an important role in theflame stabilization and flashback, which should be strengthened effectively.