摘要：There has been an intensive international effort to develop high-order Computational Fluid Dynamics(CFD) methods into design tools in aerospace engineering during the last one and half decades. These methods offer the potential to significantly improve solution accuracy and efficiency for vortex dominated turbulent flows. Enough progresses have been made in algorithm development, mesh generation and parallel computing that these methods are on the verge of being applied in a production design environment. Since many review papers have been written on the subject, I decide to offer a personal perspective on the state-of-the-art in high-order CFD methods and the challenges that must be overcome.

摘要：Numerical methods successively became important in the design and optimization of fluid machinery. However, as noise emission is considered, one can hardly find standardized prediction methods combining flow and acoustical optimization. Several numerical field methods for sound calculations have been developed. Due to the complexity of the considered flow, approaches must be chosen to avoid exhaustive computing. In this contribution the noise of a simple propeller is investigated. The configurations of the calculations comply with an existing experimental setup chosen for evaluation. The used in-house CFD solver SPARC contains an acoustic module based on Ffowcs Williams-Hawkings Acoustic Analogy. From the flow results of the time dependent large eddy simulation the time dependent acoustic sources are extracted and given to the acoustic module where relevant sound pressure levels are calculated. The difficulties, which arise while proceeding from open to closed rotors and from gas to liquid are discussed.

摘要：In order to get a high flowrate gas-gas injector and its design methodology, the combustion flow field of a typical shear-coaxial injector was analyzed firstly. The dimensional analysis was applied in the phenomenon of gas-gas combustion, and design parameter optimization and a structure improvement were also carded out. A high flowrate single-element injector with high 1-12/O2 momentum ratio and tapered 02 post tip was obtained and validated by both numerical and experimental studies. This high flowrate injector has simple construction and it can effectively enhance the mixing, decrease the combustion completion length and also has a benign heat environment. Furthermore, based on the study of the single-element injector, numerical optimization and validation experiments were conducted successively on a multi-element injector equipped with high flowrate injection elements. The multi-element injector with the high flowrate elements started up and shut down smoothly, and operated steadily without any stability aids. In the combustor designed with nominal parameters, this injection element can obtain high combustion efficiency with a flowrate of 3.7 times that of SSME main injector element and shows a benign chamber wall heat compatibility. This injector design and the design methodology can become a reference for the design of other types of injectors for liquid rocket engines.