Mixed flow turbines: Inlet and exit flow under steady and pulsating conditions
Mixed flow turbines: Inlet and exit flow under steady and pulsating conditions
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DOI：
10.1115/1.1354141
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发表时间：
2001-04-01
影响因子：
1.7
通讯作者：
Su, CC
中科院分区：
文献类型：
--
作者：
Karamanis, N;Martinez-Botas, RF;Su, CC
本文研究了高压比混合动力涡轮机在稳态和脉动工况下性能和详细的功率特性。转子设计为具有标称恒定冲角（基于蜗壳中的自由涡流），用于汽车高速柴油涡轮增压器。结果表明，偏离了涡轮增压器涡轮机设计中常用的准定常分析。来自发动机的脉动已经通过进气管和蜗壳周围被跟踪;脉冲已经被证明接近音速传播，而不是根据一些研究人员所述的整体功率速度。通过激光多普勒测速系统对进入和离开叶片的功率进行了量化。在转子前缘前3.0 mm和转子后缘后9.5 mm的平面上进行测量。涡轮机试验条件对应于29，400和41，300 rpm时的峰值效率点。结果在叶片到叶片的意义上得到解决，以更详细地检查涡轮增压器代表性条件下的功率性质。计算结果表明，冲角和出口气流角的综合影响与等熵效率之间存在着相关性。在两个流量脉冲频率下，对应于1600和2400 rpm的内燃机转速，研究了非定常流动特性。研究了四个测量平面：一个位于蜗壳进料管道中，两个位于蜗壳中（舌部下游40度和130度），一个位于涡轮机出口处。在这些平面的脉冲传播进行了研究，不同的平面上的非定常等熵效率的评价的效果被证明是显着的。总的来说，非定常性能效率结果表明，根据进口和出口流量测量结果，与相应的定常性能存在显著偏差。
The performance and detailed pow characteristics of a high pressure ratio mixed pow turbine has been investigated under steady and pulsating pow conditions. The rotor has been designed to have a nominal constant incidence (based on free vortex flow in the volute) and it is for use in an automotive high speed diesel turbocharger. The results indicated a departure from the quasi-steady analysis commonly used in turbocharger turbine design. The pulsations from the engine have been followed through the inlet pipe and around the volute; the pulse has been shown to propagate close to the speed of sound and not according to the bulk pow velocity as stated by some researchers. The pow entering and exiting the blades has been quantified by a laser Doppler velocimetry system. The measurements were performed at a plane 3.0 mm ahead of the rotor lending edge and 9.5 mm behind the rotor trailing edge. The turbine test conditions corresponded to the peak efficiency point at 29,400 and 41,300 rpm. The results were resolved in a blade-to-blade sense to examine in greater detail the nature of the pow at turbocharger representative conditions. A correlation between the combined effects of incidence and exit flow angle with the isentropic efficiency has been shown. The unsteady flow characteristics have been investigated at two flow pulse frequencies, corresponding to internal combustion engine speeds of 1600 and 2400 rpm. Four measurement planes have been investigated: one in the pipe feeding the volute, two in the volute (40 deg and 130 deg downstream of the tongue) and one at the exit of the turbine. The pulse propagation at these planes has been investigated; the effect of the different planes on the evaluation of the unsteady isentropic efficiency is shown to be significant. Overall, the unsteady performance efficiency results indicated a significant departure from the corresponding steady performance, in accordance with the inlet and exit flow measurements.