Numerical Simulation Study Of Marine Gas Turbine Of Casing Treatment

Gas turbine has more and more proportion in main power of military of large surfacewarship, axial compressor is one of the cores of modern gas turbine power plant components.The research and development of big gear power gas turbine has become the mainstream ofthe navy ship gas turbine development of all countries，so requiring the compressor has ahigher single stage compression ratio and efficiency and a higher load on the less stages，which put forward a higher and newer demands on the operation stability of the compressor.It is the significance that how to broaden the operation stability in the minimum cost. In thispaper, a ship gas turbine’s low pressure compressor as the prototype, whose low surge marginand poor economic on cruise condition is researched.1、Two models are created based on thethree of the compressor’svariablevane rotationaround the corresponding corner, which are used to simulate the conditions of the compressorat design point in oder to verify the reliability of the grid and calculation methods. Smoothwall casing of the two models in the7speed (from the low condition5000r/m to seniorconditions7500r/m) calculated to draw different speed stall, and gotfirststall dangeroussection location at different speed. Detailed analysis to the variable vanes’ impact on theoverall performanceof the compressor.2、The influence of bleed air for the stationary vane trailing edge at the casing end wallof various speed on the compressor aerodynamic performance has been analysised, whichshow that: The bleedincrease flow margin and peak efficiency and the efficiency ofstall pointslightly.3、Depth analysis of the original model with axial slot with backed chute casingtreatment for compressor aerodynamic performance, come casing treatment to reduce theefficiency of the expense to increase stability margin.4、 Explore the mechanism of circumferential grooves, comparative analysis ofcircumferential grooves slot and groove depth and slotted area on compressor performance,according to its expanding stable mechanism to optimize circumferential grooves, optimizedcasing treatment canimprove the stability margin and peak efficiencyat the same time.5、In the study of the self-recirculating casing treatment, the entry position of the ejection section of the casing, the inlet width and the inlet angle has a great influenceon thecompressor peak efficiency, and the inlet position should have a optimum value. Numericalsimulation of three self-designed self-recirculating casing treatment structure, to verify itssteady expansion effect on the multi-stage subsonic axial flow compressor, to expand stablemechanism from the change of the the compressor internal flow field, turbulent viscositychanges redistribution of traffic and high power along the leaf angle to reveal, and to arrive atthis casing treatment can get higher stability margin.The comparative analysis of the lowspeed and design speed under the different structure of the casing treatments’ impact on theoverall performance of the compressor, according to the actual demand, given the differentdesign proposals to provide a basis for engineering applications.