Numerical investigation of the influence of the tip clearance flow and the Coriolis force on the near wal flow in a compressor stage

压气机级叶顶间隙流和科里奥利力对近鲸流影响的数值研究

• 批准号: 365409499
• 负责人: Professor Dr.-Ing. Jochen Fröhlich
• 金额: --
• 依托单位: Institut für Strömungsmechanik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/365409499?language=en
• 关键词: Numerical; investigation; influence; tip; clearance

Current efforts in turbomachinery to increase pressure ratio, reduce blade count, decrease the aspect ratio, intense part load operation, etc. lead to increasing influence of flows near the side walls on the overall engine performance. Especially the operating range, losses and heat transfer are influenced by these flows. The occurring mechanisms are not fully understood although being investigated since decades. Thus the current technological progress strongly requests adequate basic research activity. This deficit will be addressed by a joint research program of four research groups at TU Dresden, UniBw München und RU Bochum, by carefully coordinated simulations and experiments to produce relevant results. Beside the investigation of heat transfer and the development of methodical tools a major goal of this joint program is the detailed analysis of the effect of system rotation. Therefor a number of specially planed and adjusted configurations will be investigated and compared with each other.Within this consortium the purpose of the project at the Chair of Fluid Mechanics, TU Dresden, is twofold. One is to investigate the physics of the secondary flow near the side walls and to contrast it with the situation in a linear cascade. The other is to contribute to a reliable turbulence-resolving simulation technology for turbomachinery grids. The physical issues will be investigated with DNS and LES for configurations experimentally investigated in partner projects, thus insuring reliable validation. These involved and well controlled simulations can yield very rich data and, for example, provide information about transition processes. Simulating configurations with and without rotation will allow studying the dependence of the near-wall flow on inflow conditions and effects generated by the system rotation, such as Coriolis force, increasing pitch with blade height, radial pressure gradients, relative motion of the end walls and shear of the inlet boundary layer. The methodologically oriented part of the work are concerned with visualization and post-processing and predominantly with assessment and development of subgrid-scale models and wall models for LES. Indeed, there exists a large demand for improved models of this type well applicable to turbomachinery flows. The analysis of the simulation data obtained will be conducted with the project partners comparing results of different methods for the same configuration - like experiment, URANS, LES - or results for different configurations among which comparisons between compressor and turbine flow thus covering a very wide parameter range.

目前涡轮机械在提高压力比、减少叶片数量、减小展弦比、剧烈部分负荷运行等方面所做的努力导致侧壁附近的流动对发动机整体性能的影响越来越大，特别是运行范围、损失和传热。尽管几十年来一直在研究，但目前的技术进步强烈要求开展足够的基础研究活动来解决这一缺陷。慕尼黑和 R.U.波鸿通过仔细协调模拟和实验来产生相关结果，除了传热研究和系统工具的开发之外，该联合计划的一个主要目标是详细分析系统旋转的影响，为此进行了一些专门计划和研究。调整后的配置将被研究并相互比较。在这个联盟中，德累斯顿工业大学流体力学主席的项目有双重目的，其一是研究侧壁附近的二次流的物理现象并对其进行对比。另一个是为涡轮机械网格提供可靠的湍流解决模拟技术，将通过 DNS 和 LES 来研究合作伙伴项目中实验研究的配置，从而确保可靠的验证。良好控制的模拟可以产生非常丰富的数据，例如，提供有关旋转和不旋转配置的信息将允许研究近壁流对流入条件和系统旋转产生的影响的依赖性，例如科里奥利力、随叶片高度增加的螺距、径向压力梯度、端壁的相对运动和入口边界层的剪切。工作的方法论部分涉及可视化和后处理，主要涉及评估和开发。事实上，对这种类型的适用于涡轮机械流动的改进模型的需求很大，项目合作伙伴将与不同方法的结果进行比较。相同的配置 - 如实验、URANS、LES - 或不同配置的结果，其中压气机和涡轮流量之间的比较，从而涵盖非常广泛的参数范围。