Optimal Design of the Volute for a Turbocharger Radial Flow Compressor

2014 ◽  
Author(s):  
Mohammad Mojaddam ◽  
Ali Hajilouy-Benisi ◽  
Mohammad Reza Movahhedy
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Radial Flow ◽  
Pressure Ratio ◽  
Radial Force ◽  
Total Pressure Loss ◽  
Effective Parameters ◽  
Flow Rates ◽  
Design Point ◽  
Flow Compressor

In this research the design methods of radial flow compressor volutes are reviewed and the main criterions in volute primary designs are recognized and most effective ones are selected. The effective parameters i.e. spiral cross section area, circumferential area distribution, exit cone and tongue area of the compressor volute are parametrically studied to identifythe optimum values. A numerical model is prepared and verified through experimental data which are obtained from the designed turbocharger test rig. Different volutes are modeled and numerically evaluated using the same impeller and vane-less diffuser. For each model, the volute total pressure ratio, static pressure recovery and total pressure loss coefficients and the radial force on the impeller are calculated for different mass flow rates at design point and off-design conditions. The volute which shows better performanceand causes lower the net radial force on the impeller, at desiredmass flow rates is selected as an optimal one. The results show the volute design approach differences at the design point and off-design conditions. Improving the pressure ratio and reducing total pressure loss at design point, may result inthe worse conditions at off-design conditions as well as increasing radial force on the impeller.

Clocking effect in a centrifugal pump with a vaned diffuser

2020 ◽  
Vol 34 (26) ◽  
pp. 2050286
Author(s):  
Fen Lai ◽  
Xiangyuan Zhu ◽  
Yongqiang Duan ◽  
Guojun Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Radial Force ◽  
Design Flow ◽  
Total Pressure Loss ◽  
Inlet Section ◽  
Centrifugal Pumps ◽  
Installation Angle

The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

Different Effects of Cantilevered and Shrouded Stators on Axial Compressor Performance

2017 ◽  
Author(s):  
Xiayi Si ◽  
Jinfang Teng ◽  
Xiaoqing Qiang ◽  
Jinzhang Feng
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Loss Coefficient ◽  
Total Pressure Loss ◽  
Axial Position ◽  
Leakage Flow ◽  
Flow Angle ◽  
Design Point ◽  
Pressure Loss Coefficient ◽  
Total Pressure Loss Coefficient

Numerical simulations with the steady 3D RANS were performed on the rear stage of a modern high pressure compressor. The labyrinth seal cavity model of the shrouded stator was simplified according to the actual stator structure, which the seal cavity gap is 1% of blade height. Several typical configurations (shrouded stator, idealized stator and cantilevered stators) were designed and carried out, and cantilevered stators contained no gap, small gap (CS1%), design gap (CS2.5%) and large gap (CS4%/CS5%). The results indicate due to the effect of leakage flow from 1% span seal cavity gap, the total pressure loss of SS is larger than IS, while IS instead of SS in the process of the compressor design, the stall margin will be enlarged nearly 6% numerically. At the design point, when the hub gap is 3.5% span clearance CS has the same loss with IS, and when the hub gap is 4.5% span clearance CS has almost the same loss with SS. Among all operation range, the total pressure loss of S1 increases with the increase of the hub clearance. When the hub gap is 0 (CS0), there is no leakage flow and the loss is the least. At the design point, comparing with SS, the total pressure loss coefficient of CS0 decreases 18.34%, CS2.5% decreases 8.46% and IS decreases 6.45%. It means if the cantilevered stator with 2.5% span hub clearance were adopted in the HPC, the performance would be better than the shrouded stator. However, because of the matching condition, the rotor that follows after cantilevered stator should be redesigned according to blade loading and inlet flow angle changed. The performance of cantilevered stator is impacted of various hub clearance, the loss below 25% span increases significantly with hub clearance, the maximum value of outlet flow angle deviation is 2.3 degree. The stator hub peak loading is shifted upstream toward the leading edge when hub clearance size is increased. The total pressure loss coefficient and pressure coefficient at different axial position had the function relation. When the hub clearance increases, the position of double leakage flow start backwards, in the rear part of stator the secondary flow becomes stronger leading to more mixing loss and lower total pressure.

scholarly journals Optimization Design and Experimental Study of Low-Pressure Axial Fan with Forward-Skewed Blades

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Li Yang ◽  
Ouyang Hua ◽  
Du Zhao-Hui
Keyword(s):  
Experimental Study ◽  
Pressure Loss ◽  
Total Pressure ◽  
Optimization Design ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Broadband Noise ◽  
Total Pressure Loss ◽  
Aerodynamic Noise ◽  
Axial Fan

This paper presents an experimental study of the optimization of blade skew in low pressure axial fan. Using back propagation (BP) neural network and genetic algorithm (GA), the optimization was performed for a radial blade. An optimized blade is obtained through blade forward skew. Measurement of the two blades was carried out in aerodynamic and aeroacoustic performance. Compared to the radial blade, the optimized blade demonstrated improvements in efficiency, total pressure ratio, stable operating range, and aerodynamic noise. Detailed flow measurement was performed in outlet flow field for investigating the responsible flow mechanisms. The optimized blade can cause a spanwise redistribution of flow toward the blade midspan and reduce tip loading. This results in reduced significantly total pressure loss near hub and shroud endwall region, despite the slight increase of total pressure loss at midspan. In addition, the measured spectrums show that the broadband noise of the impeller is dominant.

Experimental Study of the Flow and Pressure Drop Performances in Advanced Combustor Distributor Diffuser

2013 ◽  
Author(s):  
H. X. Liang ◽  
J. Q. Suo ◽  
M. Li
Keyword(s):  
Flow Field ◽  
Pressure Loss ◽  
Total Pressure ◽  
High Performance ◽  
Area Ratio ◽  
Total Pressure Loss ◽  
Pressure Recovery ◽  
Flow Rates ◽  
Turbine Engine ◽  
Outlet Flow

Gas turbine engine uses diffuser system to decelerate the compressor exit flow velocity before it enters combustor, it is important to design the compact structure and high performance of the diffuser for gas turbine engine. The diffuser and combustor dome configurations are critical flow path parameters in the design of a low-pressure-loss, high-performance combustion system. With rising of the inlet Mach number of the combustor, dramatically increasing of the diffuser total pressure loss and flow separation. So a new distributor diffuser was designed. In this paper preliminary results from an experimental investigation into the aerodynamic performance on a rectangle combustor-diffuser system with seven distributor plates were presented. Measurements were taken in the diffuser section to assess the diffuser performance characteristics under various conditions, the appropriate outlet flow field can be attained by changing the plate area ratio and form. Tests were carried out to investigate the influence of distributor diffuser plate geometry. During these measurements for each parametric configuration, data were obtained at 24 different flow rates through the distributor diffuser, it gave the conclusion that the distributor diffuser area ratio could be more than traditional diffusers with shorter construction and higher pressure recovery performance, while the flow loss through it was not beyond the traditional limit. Overall static pressure recovery improves and overall total pressure loss reduces with increasing distributor diffuser area ratio, and the increased flow rates through the distributor diffuser gave rise to a higher total pressure loss. The total pressure loss fraction was less than 2.5% when Mach number changed from 0.3 to 0.38; if the area ratio was more than 2.1, the diffuser loss coefficient remained less than 0.3, pressure recovery coefficient more than 0.5 and area ratio up to 2.45. There exists an area ratio in 1.6∼2.0 which makes diffuser outlet flow field distribution more uniform; Baffle structure can adjust the flow field distribution of outlet diffuser. As a result, the distributor diffuser can be potentially satisfied with demands for high performance combustor.

Numerical Investigation of the Effect of an Axial Pre-Swirl Nozzle With a Radial Angle in a Pre-Swirl Rotor-Stator System

2021 ◽  
Author(s):  
Gang Zhao ◽  
Shuiting Ding ◽  
Tian Qiu ◽  
Shenghui Zhang
Keyword(s):  
Gas Turbines ◽  
Pressure Loss ◽  
Total Pressure ◽  
Discharge Coefficient ◽  
Pressure Ratio ◽  
Temperature Drop ◽  
Tangential Velocity ◽  
Total Pressure Loss ◽  
Adiabatic Effectiveness ◽  
Cooling Air

Abstract Pre-swirl nozzles are often used in gas turbines to deliver the cooling air to the turbine blades. The static axial nozzles swirl the cooling air in the direction of rotation of the turbine disk, thereby reducing the relative total temperature of the air. Most studies about nozzles focus on its shape, radial location, tangential angle to reduce the pressure loss and increase the temperature drop of the pre-swirl system, but few of them consider the benefit of a radial angle of nozzles. This paper investigated numerically the performance of a pre-swirl system whose pre-swirl nozzles have a radial angle. Six radial angles are selected to study the flow dynamics of a direct-transfer pre-swirl system in terms of the total pressure loss coefficient of the pre-swirl cavity, the discharge coefficient of the receiver holes, and the adiabatic effectiveness. It is shown that the nozzles with radial angles can adjust the tangential velocity and radial velocity and thus can influence the performance of a pre-swirl system. There is a lowerest value of total pressure loss in pre-swirl cavity, that is α = 90°, which can hardly be influenced by the radial angle of nozzle and pressure ratio π. For a specific swirl ratio β∞, there exists an optimal αopt where the discharge coefficient of receiver hole is maximum. Moreover, αopt decreases as pressure ratio π increases. And so is the adiabatic effectiveness Θad.

The Effect of Tip Clearance and Hub Rotation on the Performance of an Axial Compressor Stator

2019 ◽  
Author(s):  
Chao Jiang ◽  
Jun Hu ◽  
Jiayu Wang ◽  
Jun Li ◽  
Rong Xu
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Important Influence ◽  
Tip Clearance ◽  
Total Pressure Loss ◽  
Computation Method ◽  
Efficiency Curve ◽  
Total Pressure Ratio

Abstract In this paper, 1.5-stage high-speed compressor stator was studied using numerical computation method. Four gap cases were calculated under the condition of the hub being stationary or rotating, and the characteristic curves of the 1.5-stage compressor was obtained. Firstly, the influence of the change of the gap on the total pressure ratio and the efficiency curve was studied when the state of the hub is fixed. Then, the influence of the rotation of the hub on the total pressure ratio and the efficiency curve was discussed when the tip clearance is fixed. Finally, the total pressure loss of the stator channel would be analyzed. The above research would make people understand that the relative motion of the end wall has an important influence on the performance of the axial-flow compressor; when hub is stationary, the optimal gap is greater than 0, while when hub was rotating, the optimal gap was 0; and recognize that the variation of clearance and the motion state of the hub have an important influence on the distribution of total pressure loss along the span.

Numerical Study on the Effects of Blade Leading Edge Shape to the Performance of Supersonic Rotor

2003 ◽  
Author(s):  
Kicheol Park
Keyword(s):  
Rotational Speed ◽  
Pressure Loss ◽  
Total Pressure ◽  
Performance Test ◽  
Numerical Study ◽  
Pressure Ratio ◽  
Leading Edge ◽  
Total Pressure Loss ◽  
Manufacturing Cost ◽  
Blade Leading Edge

Recently, it is required to design a fan and compressor with higher stage pressure ratio while maintaining adiabatic efficiency high also. To increase the stage pressure ratio, blade rotational speed or diffusion factor should be increased. In the case of increased rotational speed, relative speed of flow at blade leading edge is well supersonic. With supersonic rotor blade, total pressure loss is mainly due to leading edge shock waves and the thickness should be thin enough to minimize this. As a result, the blade is like to be week in terms of mechanical strength and the manufacturing cost would be increased because high-precision NC machining is required. Furthermore, it is one of the biggest hurdles to maintain proper level of thickness while one making small stages. In this paper, aerodynamic performance of supersonic rotor blades with different leading edge thickness and shapes are calculated using the finite volume method. The effects of blade leading edge shape and thickness to the performance are investigated especially in terms of total pressure loss and the already known loss correlations of leading edge thickness are examined. Subsequently this will be verified by performance test on rig.

Effect of the end-wall vortex generator jets on the performance of a high subsonic compressor cascade

2018 ◽  
Vol 233 (3) ◽  
pp. 324-336
Author(s):  
Cong Chen ◽  
Huaping Liu ◽  
Fu Chen
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Numerical Study ◽  
Vortex Generator ◽  
Total Pressure Loss ◽  
Experimental Result ◽  
Compressor Cascade ◽  
Design Point ◽  
Vortex Generator Jets ◽  
End Wall

This paper presents a numerical and experimental result of the end-wall vortex generator jets for controlling corner separation and enhancing the aerodynamic performance in a high subsonic (Ma = 0.7) compressor cascade. The experiments were carried out on a compressor cascade at design point ( i = 0°) and off-design points ( i = −2°, 2°, and 4°). At design point, the total pressure loss coefficient could be reduced up to 12.1%.With the increase in the incidence, the control effect is enhanced first and then reduced. The maximum total pressure loss reduction is up to 14.6% when the incidence is 2°. The numerical study is further conducted to analyze the flow pattern and the vortex structure. The jet vortex is formed downstream of the jet hole using the vortex generator jets, the cross flow on the end wall is also suppressed.

scholarly journals Accurate 2-D Modelling of Transonic Compressor Cascade Aerodynamics

Aerospace ◽  
2019 ◽  
Vol 6 (5) ◽  
pp. 57 ◽  
Author(s):  
Tommaso Piovesan ◽  
Andrea Magrini ◽  
Ernesto Benini
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Loss Coefficient ◽  
Total Pressure Loss ◽  
Compressor Cascade ◽  
Transonic Compressor ◽  
Pressure Loss Coefficient ◽  
Total Pressure Loss Coefficient

Modern aeronautic fans are characterised by a transonic flow regime near the blade tip. Transonic cascades enable higher pressure ratios by a complex system of shockwaves arising across the blade passage, which has to be correctly reproduced in order to predict the performance and the operative range. In this paper, we present an accurate two-dimensional numerical modelling of the ARL-SL19 transonic compressor cascade. A large series of data from experimental tests in supersonic wind tunnel facilities has been used to validate a computational fluid dynamic model, in which the choice of turbulence closure resulted critical for an accurate reproduction of shockwave-boundary layer interaction. The model has been subsequently employed to carry out a parametric study in order to assess the influence of main flow variables (inlet Mach number, static pressure ratio) and geometric parameters (solidity) on the shockwave pattern and exit status. The main objectives of the present work are to perform a parametric study for investigating the effects of the abovementioned variables on the cascade performance, in terms of total-pressure loss coefficient, and on the shockwave pattern and to provide a quite large series of data useful for a preliminary design of a transonic compressor rotor section. After deriving the relation between inlet and exit quantities, peculiar to transonic compressors, exit Mach number, mean exit flow angle and total-pressure loss coefficient have been examined for a variety of boundary conditions and parametrically linked to inlet variables. Flow visualisation has been used to describe the shock-wave pattern as a function of the static pressure ratio. Finally, the influence of cascade solidity has been examined, showing a potential reduction of total-pressure loss coefficient by employing a higher solidity, due to a significant modification of shockwave system across the cascade.

scholarly journals Investigation of the Effects of Different Working Fluids on Compressor Cascade Performance

2021 ◽  
Vol 11 (5) ◽  
pp. 1989
Author(s):  
Zhitao Tian ◽  
Chengze Wang ◽  
Qun Zheng
Keyword(s):  
Physical Properties ◽  
Specific Heat ◽  
Pressure Loss ◽  
Total Pressure ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Total Pressure Loss ◽  
Compressor Cascade ◽  
Working Fluids ◽  
Specific Heat Ratio

The compressor of closed Brayton cycle (CBC) plant operating with working fluid other than air is a vital element of the energy conversion unit. However, due to insufficient understanding of the influence of the physical properties of working fluids on the performance of the compressor, the actual working conditions and design conditions of the compressor’s performance deviate greatly. In this paper, the objective is to analyze the influence mechanism of the physical properties on the performance of the cascade of compressor (static pressure ratio and total pressure loss coefficient). Therefore, the impact of a specific heat ratio on the performance of the compressor cascade is studied utilizing carbon dioxide (γ = 1.29), air and carbon monoxide (γ = 1.4), argon and helium (γ = 1.667). Moreover, the relationships of static pressure ratio and total pressure loss coefficient with physical properties of the working fluids are analyzed in the compressor cascade. It is established that a higher specific heat ratio fluid gives a higher coefficient of total pressure loss and static pressure ratio in contrast to smaller specific heat ratio at matching inlet Reynolds number and Mach number.

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