共查询到19条相似文献,搜索用时 506 毫秒
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跨音速离心压气机级间静压测量研究 总被引:1,自引:0,他引:1
为获得车用涡轮增压器离心压气机各元件进出口及周向静压分布,开展了跨音速离心压气机级间静压测试研究。研究结果表明:蜗舌结构未造成导风轮进口静压分布周向不均匀(导风轮进口周向压力波动在2.5 kPa之内);蜗舌结构导致短叶片轮缘静压分布的周向不均匀性;同一转速下,跨音速流动最高效率工况周向静压分布不均匀;叶轮跨音速时,蜗壳沿着流动方向进行减速扩压;同一转速下,扩压器静压提升变化很小(约在3 kPa之内),而叶轮静压提升变化很大(约13~50 kPa),叶轮静压提升的改变决定压比流量特性线的陡峭程度。 相似文献
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为了探索在超跨音速下具有优良启动特性的叶型,以某跨音速叶型为例,初步尝试设计海豚叶型,并对其流场进行了数值模拟,以评估这种叶型是否适合于超跨音速流动。 相似文献
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热力叶轮机械内部的全三维复杂流动数值模拟研究点滴 总被引:1,自引:0,他引:1
简要回顾了将计算流体力学用于热力叶轮机械研究方面的部分工作。采用作者提出的高收敛率、高精度和高分辩率的数值计算方法,对热力叶轮机械内部的三维非定常湍流流动进行了数值模拟,并与实验结果进行了比较。表明现在的方法和程序有更高的精度和分辩率、更高的计算效率,数值格式简单,能有效地捕捉各种复杂流动现象。可作为一种有力的工具提供给工程师进行一般的叶轮机械叶片的设计与优化选型。 相似文献
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基于试验测试数据建立增压柴油机的仿真模型,开展0~4 000m高原适应性研究工作,研究增压柴油机性能及压气机性能海拔变化关系,并研究不同海拔下压气机内部流动状况,分析压气机效率下降原因。研究结果表明:高海拔工况下,柴油机功率、转矩与燃油消耗率下降,进气流量减少,增压压力下降,压气机压比增大,效率下降。压气机子午面的相对总压的低压区域压力较小,叶顶间隙间及叶轮出口高熵值区域增大且范围提前。跨音速流动区域增大,激波损失增大,叶顶间隙流加强,泄漏损失增大,分流叶片压力侧主流与低速泄漏流掺混,尾迹区域增大,掺混损失增加,压气机叶轮内部损失增大。因此高原环境下,压气机效率降低。 相似文献
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本文以某液化天然气(LNG)流程中增压透平膨胀机的增压器叶轮为例,应用商业软件FLUENT,以RNGk-ε二方程湍流模型为基础,对叶轮内部流动进行了三维粘性稳态数值模拟.通过模拟得到叶轮内部流体的相对速度、压力分布,分析了叶轮内部经常出现的流动分离、二次流、尾迹等复杂流动现象.为减少叶轮内部的流动损失,对叶片的前缘进行了修改,并对原始设计、圆形和椭圆形前缘的叶轮流场分别进行了模拟与分析.结果表明,椭圆形前缘有效地抑制流动分离,对叶片气动性能就有良好的改善作用. 相似文献
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对一项新的设计技术-端壁造型技术的发展历史进行了回顾.端壁造型技术可以降低端壁区二次流损失,其提高效率的作用已经在涡轮中得到了广泛的验证,相关结论可以直接被工程采用.端壁造型技术在压气机中的研究虽晚于其在涡轮中的研究,但最新研究表明:端壁造型在改变跨音压气机激波结构,改善压气机稳定工作裕度,以及降低静叶角区分离等领域能够发挥一定作用.端壁造型技术反应了人们利用复杂型面来提高叶轮机械性能的研究趋势,值得研究者在未来开展更深入的研究. 相似文献
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The rotor blade height with low hub-tip ratio is relatively longer,and the aerodynamic parameters change drastically from hub to tip.Especially the organization of flow field at hub becomes more difficult.This paper takes a transonic 1.5-stage axial compressor with low hub-tip ratio as the research object.The influence of four types of rotor hub contouring on the performance of transonic rotor and stage is explored through numerical simulation.The three-dimensional numerical simulation results show that different hub contourings have obvious influence on the flow field of transonic compressor rotor and stage,thus affecting the compressor performance.The detailed comparison is conducted at the rotor peak efficiency point for each hub contouring.Compared with the linear hub contouring,the concave hub contouring can improve the flow capacity,improve the rotor working capacity,and increase the flow rate.The flow field near blade root and efficiency of transonic rotor is improved.The convex hub contouring will reduce the mass flow rate,pressure ratio and efficiency of the transonic rotor.Full consideration should be given to the influence of stator flow field by hub contouring. 相似文献
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IntroductionA rapid expansion of moist air or steam in asupersonic nozzle gives rise to nonequilibriumcondensation phenomena. Thereby, the nozzle flow isaffected by the latent heat released by condensation ofwater vapouf, and if the heat released exceeds a certainquantity, a condensation shock wave will occur[1-4].Many works for the passive contfol of shockboundary layer interaction using the porous wall with aplenum underneath have been repofted on the applicationof the technique tO tfansonic… 相似文献
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This paper presents a numerical analysis of the atmospheric air transonic flow through de Laval nozzles.By nature,atmospheric air always contains a certain amount of water vapor.The calculations were made using a Laval nozzle with a high expansion rate and a convergent-divergent (CD) "half-nozzle",referred to as a transonic diffuser,with a much slower expansion rate.The calculations were performed using an in-house CFD code.The computational model made it possible to simulate the formation of the liquid phase due to spontaneous condensation of water vapor contained in moist air.The transonic flow calculations also take account of the presence of a normal shock wave in the nozzle supersonic part to analyze the effect of the liquid phase evaporation. 相似文献
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论述了时间相关有限差分法在跨音速叶栅流动计算中的应用,并以具有代表性的跨音速压气机叶栅流场的计算和图样的制取为例,附以程序编制及其流程图,详细地讲解了计算程序的具体操作。由比较可以看出此方法较以前的时间推进法要快得多。可以预期,随着该方法的不断完善,得到更为精确的结果是完全有可能的。 相似文献
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研究表明,迷宫气封中的振荡气流对机组的稳定性有一定的影响。由流场作用在转子上不平衡的气动力是产生自激振动的主要原因。当转子有偏心时,这种不平衡的气动力的作用就更加明显。本文采用混合有限分析解法,引入转子偏心距对转子动特性系数的影响,找出偏心距对转子动特性系数影响的规律。分析结果表明:随着偏心距的增大,转子的动特性系数也急剧变化。 相似文献
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This paper describes experimental and numerical works to investigate noise phenomenon in supersonic flow dis- charged from a convergent-divergent nozzle. The noise phenomenon of flow is generated by an emission of 'transonic tones'. The results obtained show that the frequency of a transonic tone, that differs from the frequency of a screech tone due to the shock-cell structures in a jet and originates in the shock wave in the nozzle, increases in proportion to the nozzle pressure ratio. The high-order transonic tone has the directivity in the direction of the flow. As for the transonic tone's frequency, the separated zone was calculated by using a simple flow model con- sidering the propagating perturbation. The results of the model corresponded to the results of this experiment well. 相似文献