航空发动机在国防建设和国民经济中占有至关重要的地位。压气机是航空发动机的核心部件。单级离心压气机是小功率级涡轴发动机主要的压气机构型。提高单级离心压气机的压比，是现代先进涡轴发动机的发展趋势。本文采用全三维数值仿真方法，对单级压比超过12.0的超高压比离心压气机的气动设计开展了研究，并探索了倾掠特征技术和流动扩稳技术对超高压比离心压气机的影响规律和流动控制机理。 论文完成了超高压比离心压气机的气动设计。探索了超高压比离心压气机叶轮的损失来源，并建立了超高压比离心压气机从一维到三维的气动设计方法。基于三维仿真方法，对叶轮分流叶片气动布局和出口宽度、径向扩压器宽度和进口角度、轴向扩压器进口角度和叶片数等关键几何特征下的压气机性能和流场进行了分析。数值分析算结果表明，所设计的单级超高压比离心压气机总压比达到13.1，等熵效率达到79.8%。 论文分析了采用倾掠特征技术后超高压比离心叶轮效率下降的流动机理。研究发现，叶轮前缘倾特征和掠特征两种三维造型技术对超高压比离心叶轮效率的提升能力较弱，甚至会降低叶轮效率。对倾特征的流动机理研究表明，倾特征在高叶高区域会影响叶轮出口附近的间隙流损失；在低叶高区域会影响中叶片出口尾迹区。对掠特征的流动机理研究表明，掠特征在高叶高区域会影响通道内流动分离的产生位置；在低叶高区域会影响主叶片压力面和短叶片吸力面的分离区；在轮毂附近会影响中叶片出口尾迹区。 论文探究了流动扩稳技术对超高压比离心压气机的扩稳效果及流动机理。对机匣处理装置的下游槽道位置和下游槽道宽度进行了参数化研究，将压气机稳定工作范围由无机匣处理的3.9%拓宽至8.3%。研究发现，机匣处理技术能够扩稳的主要原因有两个，其一是机匣处理装置减小了叶轮进口的叶片负载，激波面和吸力面低速流体的位置更靠近下游，避免了进口处的流体堵塞，提高了压气机的流通能力；其二是上游槽道的射流效应使叶轮进口流量增大，攻角减小，从而拓宽了压气机的稳定工作范围。此外，还针对高压比离心压气机进行了定常射流技术的初步探索。通过降低激波和间隙涡的强度、减小叶尖气流攻角，射流技术成功地提高了压气机的稳定工作范围。

Aeroengines play a pivotal role in national defense construction and the national economy. Compressors are core components of aircraft engines. The single-stage centrifugal compressors are the main configuration of compressors for low-power turboshaft engines. Increasing the pressure ratio of single-stage centrifugal compressors is the development trend of modern advanced turboshaft engines. The aerodynamic design of a single-stage centrifugal compressor with an ultra-high pressure ratio exceeding 12.0 has been investigated by three-dimensional numerical simulation methods in this thesis. The effects and flow control mechanisms of the lean and sweep features and flow control methods to improve stability on the ultra-high pressure ratio centrifugal compressor have also been explored. The aerodynamic design of the ultra-high pressure ratio centrifugal compressor has been completed in the thesis. The sources of losses of ultra-high pressure ratio centrifugal compressor are explored. The aerodynamic design method of ultra-high pressure raito centrifugal compressor from one to three dimensions are established. Based on three-dimensional simulation methods, the compressor performance and flow field under different key geometric features, such as the splitters aerodynamic configuration and outlet width of the impeller, the width and inlet angle of the radial diffuser, the inlet angle and the blade number of the axial diffuser, have been analyzed. The numerical analysis results show that the designed single-stage ultra-high pressure ratio centrifugal compressor has a total pressure ratio of 13.1 and an isentropic efficiency of 79.8%. The flow mechanisms of the lower efficiency of the ultra-high pressure ratio centrifugal compressor with lean and sweep features have been investigated in the thesis. Results show that the two three-dimensional features - lean and sweep at the leading edge of the impeller - have little contribution in improving the efficiency of the ultra-high pressure ratio centrifugal impellers, and even reduce the impeller efficiency.Researches on the flow mechanism of the lean feature show that the tip clearance flow loss near the impeller outlet is affected at the high blade span; the wake area of middle blades is affected at the low blade span when the lean angles are different. Researches on the flow mechanism of the sweep feature show that the occurrence of flow separation in the channel is affected at at the high blade span; the separations near the main blade pressure surface and the splitters suction surface is affected at the low blade span; the wake area of middle blades is affected near the hub when the sweep angles are different. The effects on improving stabilities and flow mechanisms of the flow control methods on the ultra-high pressure ratio centrifugal compressor have been investigated in the thesis. The stable flow range has been improved from 3.9% of the compressor without casing treatments to 8.3% through the researches of the downstream channel position and downstream channel width of the casing treatment. Researches show that there are two main reasons for the stability improvement of casing treatments. The blade loading at the impeller inlet is reduced and positions of the shock wave surface and the low-momentum fluids on the suction surface move towards the downstream. The occurrence and development of the oblique shock wave and tip clearance flow at the impeller inlet is suppressed. This will avoid the flow blockage at the inlet and improves the compressor's flow capacity. Another reason is the jet effects at the upstream channel of casing treatments increase the inlet mass flow of the impeller and reduces the incidence. As a result, the stable flow range of the compressor with casing treatments has been widen significantly. Moreover, a preliminary exploration of steady injection technology for high pressure ratio centrifugal compressor is also conducted. The stable flow range of the compressor is successfully increased by using tip injection. The mechanisms are that the intensity of shock wave and tip clearance vortex is reduced and the tip incidence is decreased.