Papers by Keyword: Combustor

Abstract: The cold flow field in a two dimensional cavity of supersonic combustor has been simulated numerically by using the compressible flow Navier-Stokes equation with the κ-ω SST turbulence model. The flow field structure of different cavity aft wall slope angle (16°,30° and 90°) , different fore aft wall height ratio (1 and 2) and different length depth ratio (3 and 5) are analyzed. The conclusions are as follows: As cavity aft wall slope angle decreases, the compression wave formed at cavity leading separation corner shifts into expansion wave, the shear layer moves into cavity gradually; As cavity fore aft wall height ratio increases from one to two, the expansion wave formed at cavity leading separation corner strengthens and there is no compression wave formed at;As cavity length depth ratio increases from three to five, the compression or expansion wave formed at cavity leading separation corner weakens, cavity bottom wall pressure tends to be constant and aft wall pressure rises.

Abstract: A twin annular premixing swirler (TAPS) combustor model of low emissions was developed in this study. And computational studies on combustion process in the combustor model were carried out. Standard k-ε Turbulence Model, PDF non-premixed combustion model, Zeldovich thermal NOx formation model and DPM two-phase model were employed. The distributions of some key performance parameters such as gas temperature, flow velocity, concentrations of NOx and CO emissions were obtained and analyzed. At the same time, combustion mechanics inside the TAPS combustor model were investigated. The computational results indicated that the TAPS combustor employed in this study does a better job of improving key combustion performances such as combustion efficiency, total pressure recovery and outlet temperature distribution factor, and reducing NOx and CO emissions at the same time.

Abstract: The thermal protection is a key factor to keep the gas generator work longtime under high temperature condition steadily. The main heat transfer paths are analyzed. A numeral simulation of the combustor and its nozzle shows the pipe outside temperature distribution with the change of time, position and thickness. According to the numeral simulation results, two thermal protection measures are bring forward, reduce the temperature, choosing proper thickness and heat resisting material. At last, an experiment results validate that the numeral simulation is credibility; the improvement of the structure is effective. With a longtime run, the outside wall temperature is 870K, which satisfies the operation needs.

Abstract: Keeping exhaust gas temperature constant in oxygen enriched and flue gas circulating Micro Gas Turbine, Numerical Research is carried on to study inlet temperatures influence on combustion characteristics. Simulation shows that along with increase of methanes temperature, combustion efficiency increase slightly, uniformity coefficient of outlet temperature decreases, total pressure recovery coefficient decreases, content of carbon monoxide and methane in outlet gas decrease. However, when inlet methanes temperature exceed 100 °C, content of NOx increase rapidly in flue gas. The simulation result supplied reference for design of oxygen enriched and flue gas circulating combustor.

Abstract: The effect of the cavity design parameters on the integrated performance parameter net thrust of hypersonic vehicle was investigated by computer numerical simulation methods in this paper. The cavity design parameters include position value XL and length-to-depth ratio L/D. The research purpose of the paper is to develop ideas for the integrated design of hypersonic vehicle. The studied results show that the effect curve charts of the ratio L/D on net thrust are similar at variable cavity positions. The extreme value of net thrust is obtained at some value of L/D. The fuel mixture touch underside step of the combustor easily to cause eddy loss which make against combustion and lead to net thrust descend while the cavity locates down step in the combustor. While the position of cavity on more combustor back, the combustion process is not built completely and the gas is exhausted quickly, which induces the more net thrust loss.

Abstract: Method of CFD is used in this paper to simulate and calculate velocity field, temperature field and droplet track in PCZ(primary combustion zone) under the 3D two phase turbulent combustion for the ground idling, the peak, the middling and the altitude-small lever flying conditions. By analyzing the calculation results and comparing with tests, characters of PCZ are well investigated.

Abstract: A numerical insight was accomplished to optimize the scramjet combustor configuration based on orthogonal experimental design. Parametric modeling of combustor configurations was performed by the orthogonal array with 13 factors at 3 levels. Numerical simulations were proceeded by k-ε standard turbulence model and eddy-dissipation model in the combustion process. The performance indexes of combustion efficiency, total pressure recovery coefficient and thrust gain coefficient were evaluated. Detailed comparison with the effect of the factors on the performance was also carried out to demonstrate the main factors and determine the optimal configuration. The analysis of the extreme differences of the factors indicates that the main factors affecting combustion efficiency were the length of the wedge, the length depth ratio of the cavity, the depth of the cavity, and the length of the expanding section; The main factors affecting total pressure recovery coefficient are the angle of the primary combustor, the length of the expanding section, and the thickness of the strut; The main factors affecting thrust gain coefficient are the thickness of the strut, the length of the expanding section, and the angle of the secondary combustor. Validation of the optimal configuration is then confirmed that its performance is higher than the rest of the configurations, with the combustion efficiency of 0.915 and the total pressure recovery coefficient of 0.486, which are 31.5% and 65.9% higher than the experimental results, respectively.

Abstract: Experimental study on combustor outlet temperature field of heavy-duty gas turbine had been finished on high-pressure test system. Experimental results indicate: The OTDF is sensitive to diameter of dilution holes, and the RTDF is sensitive to location of dilution holes. The test results have important guiding significance and reference value to design, commission and working about the similar combustor.

Abstract: Numerical simulation of the performance of QD128 gas turbine combustor was finished using CFD method. The results indicate: The flow meter distribution of combustor is reasonable, and the velocity field of combustor meets the design requirements. Outlet average temperature is 1298K, hot spot temperature is 1486K, the temperature distribution curve meets the design requirements, and OTDF=0.280，RTDF=0.086，which are slightly higher than the level of prototype aircrafts. The results enrich the design data of QD128 gas turbine, and provide reliable reference for the running and improving.

Abstract: Through the set up of a calculation model on film cooling in the primary zone of an annular combustor, a parametrical study was made on the relationship of film cooling effectiveness and wall temperature with configuration parameters such as cooling slot height and TBC thickness. Through parametrical study, it can be seen that with all the parameters kept the same and even the resulting effectiveness of the outer liner slightly greater due to a slightly higher blow ratio, the outer liner temperatures are considerably higher than the inner liner temperatures. The calculation shows, with cooling effectiveness, there are optimum values of coolant injection angle and film cooling slot height, while there is a monotonous tendency for the relationship of cooling effectiveness with other parameters such as tapered angle on nugget lip, starting edge angle at nugget-slot exit and lip thickness .The study demonstrates that the higher the TBC thickness, the lower the highest value of base metal temperatures, but when the TBC thickens, it becomes heavier, and the possibility of TBC spallation gets greater.