High Efficiency Low Flow Rate Centrifugal Compressor for The More Electric Aircraft

1994 ◽  
Author(s):  
F. Gui ◽  
T. R. Reinarts ◽  
R.P. Scaringe ◽  
Joseph M. Gottschlich
Author(s):  
Sasuga Ito ◽  
Masato Furukawa ◽  
Satoshi Gunjishima ◽  
Takafumi Ota ◽  
Kazuhito Konishi ◽  
...  

Abstract Inlet distortion has influence on the aerodynamic performance of turbomachinery such as compressors, turbines and fans. On turbochargers, bent pipes are installed around the compressor due to the spatial limitations in the engine room of the vehicle. As the result, the compressor is operated with the distorted inflow. In the low flow rate operation, the distorted inflow also affects the flow instability like stall and surge. Especially, the operation range on the low flow rate side is defined based on the flow rate where surge occurs, so it is important to investigate the effect of the distorted inflow on surge. In this study, the effect of the inlet distortion to surge phenomena has been investigated by the experiments with a transonic centrifugal compressor. A bent pipe has been installed at the upstream of the compressor to generate a distorted flow. Experiments have been also conducted under the condition that a straight pipe was installed upstream of the compressor, and unsteady measurements with high response pressure sensors and an I-type hot wire probe have been carried out to each experiments. In addition, Fast Fourier transform (FFT) and Wavelet transform have been applied to the unsteady measurement results obtained from each experiment.


1995 ◽  
Vol 61 (591) ◽  
pp. 3848-3853
Author(s):  
Yasuyuki Komatsubara ◽  
Atsutaka Muto ◽  
Hoshio Tsujita ◽  
Shimpei Mizuki

2018 ◽  
Vol 245 ◽  
pp. 09002 ◽  
Author(s):  
Aleksey Yablokov ◽  
Ivan Yanin ◽  
Aleksey Danilishin ◽  
Anatoliy Zuev

The article presents results of applying the methods of computational fluid dynamics for model low-flow rate stages of centrifugal compressors with flow rate coefficient F = 0.028. The computational domain of a model centrifugal compressor for CFD-simulation consists of the following elements: inlet chamber, impeller, vaneless diffuser, return channel, outlet chamber, shaft seal labyrinth, front and back shroud leakage. Full-scale experimental studies were conducted to model stage 028 in air at an inlet pressure of p* = 1 atm. Numerical research for stage 028 held with flow rate coefficient F=(0.019-0.046) for three variants trailing edge of the impeller. According to the results of numerical research are constructed performances of stages centrifugal compressor and conducted verification of results. Estimated discrepancy between the results of numerical researches on the model with shaft seal labyrinth and without shaft seal labyrinth.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042199886
Author(s):  
Wenzhe Kang ◽  
Lingjiu Zhou ◽  
Dianhai Liu ◽  
Zhengwei Wang

Previous researches has shown that inlet backflow may occur in a centrifugal pump when running at low-flow-rate conditions and have nonnegligible effects on cavitation behaviors (e.g. mass flow gain factor) and cavitation stability (e.g. cavitation surge). To analyze the influences of backflow in impeller inlet, comparative studies of cavitating flows are carried out for two typical centrifugal pumps. A series of computational fluid dynamics (CFD) simulations were carried out for the cavitating flows in two pumps, based on the RANS (Reynolds-Averaged Naiver-Stokes) solver with the turbulence model of k- ω shear stress transport and homogeneous multiphase model. The cavity volume in Pump A (with less reversed flow in impeller inlet) decreases with the decreasing of flow rate, while the cavity volume in Pump B (with obvious inlet backflow) reach the minimum values at δ = 0.1285 and then increase as the flow rate decreases. For Pump A, the mass flow gain factors are negative and the absolute values increase with the decrease of cavitation number for all calculation conditions. For Pump B, the mass flow gain factors are negative for most conditions but positive for some conditions with low flow rate coefficients and low cavitation numbers, reaching the minimum value at condition of σ = 0.151 for most cases. The development of backflow in impeller inlet is found to be the essential reason for the great differences. For Pump B, the strong shearing between backflow and main flow lead to the cavitation in inlet tube. The cavity volume in the impeller decreases while that in the inlet tube increases with the decreasing of flow rate, which make the total cavity volume reaches the minimum value at δ = 0.1285 and then the mass flow gain factor become positive. Through the transient calculations for cavitating flows in two pumps, low-frequency fluctuations of pressure and flow rate are found in Pump B at some off-designed conditions (e.g. δ = 0.107, σ = 0.195). The relations among inlet pressure, inlet flow rate, cavity volume, and backflow are analyzed in detail to understand the periodic evolution of low-frequency fluctuations. Backflow is found to be the main reason which cause the positive value of mass flow gain factor at low-flow-rate conditions. Through the transient simulations of cavitating flow, backflow is considered as an important aspect closely related to the hydraulic stability of cavitating pumping system.


2013 ◽  
Vol 842 ◽  
pp. 530-535 ◽  
Author(s):  
Zeng Meng Zhang ◽  
Yong Jun Gong ◽  
Jiao Yi Hou ◽  
Han Peng Wu

The water hydraulic reciprocating plunger pump driven by linear motor is suitable to deep sea application with high efficiency and variable control. Aiming to study the principle structure and working characteristics of the pump, two patterns of valve and piston distribution were designed. And the control method and the performance were analyzed by simulation based on the AMESim model. The results show that the pressure and flow pulsation of piston type pump are much smaller than the valve type, even though the piston type is large in scale and works at low flow rate. Compared with a valve distribution tri-linear-motor reciprocating plunger pump (VDTLMP), as the flow rate of the piston distribution double linear motor reciprocating plunger pump (PDDLMP) is decreased from 36.7 L/min to 21.2 L/min theoretically, the pressure pulsation amplitude is decreased from 46% to 2%, and the flow pulsation rate is also decreased from 0.266 to 0.007. These results contribute to the research on deep-sea water hydraulic power pack and direct drive pump with high efficiency and energy conservation.


Author(s):  
Xuwen Qiu ◽  
David Japikse ◽  
Mark Anderson

Flow recirculation at the impeller inlet and outlet is an important feature that affects impeller performance, especially the power consumption at a very low flow rate. Although the mechanisms for this flow phenomenon have been studied, a practical model is needed for meanline modeling of impeller off-design performance. In this paper, a meanline recirculation model is proposed. At the inlet, the recirculation zone acts as area blockage to relieve the large incidence of the active flow at a low flow rate. The size of the blockage is estimated through a critical area ratio of an artificial “inlet diffuser” from the inlet to throat. The intensity of the reverse flow can then be calculated by assuming a linear velocity profile of meridional velocity in the recirculation zone. At the impeller outlet, a recirculation zone near the suction surface is established to balance the velocity difference on the pressure and suction sides of the blade. The size and the intensity of the outlet recirculation zone is assumed related to blade loading, which can be evaluated based on flow turning and Coriolis force. A few validation cases are presented showing a good comparison between test data and prediction by the model.


Sign in / Sign up

Export Citation Format

Share Document