Numerical and Experimental Investigation of Return Channel Vane Aerodynamics With Two-Dimensional and Three-Dimensional Vanes

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
A. Hildebrandt ◽  
F. Schilling
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Static Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Field Performance ◽  
Two Dimensional ◽  
Flow Angle ◽  
Overall Performance ◽  
Return Channel

The present paper deals with the numerical and experimental investigation of the effect of return channel (RCH) dimensions of a centrifugal compressor stage on the aerodynamic performance. Three different return channel stages were investigated, two stages comprising three-dimensional (3D) return channel blades and one stage comprising two-dimensional (2D) RCH vanes. The analysis was performed regarding both the investigation of overall performance (stage efficiency, RCH total pressure loss coefficient) and detailed flow-field performance. For detailed experimental flow-field investigation at the stage exit, six circumferentially traversed three-hole probes were positioned downstream the return channel exit in order to get two-dimensional flow-field information. Additionally, static pressure wall measurements were taken at the hub and shroud pressure and suction side (SS) of the 2D and 3D return channel blades. The return channel system overall performance was calculated by measurements of the circumferentially averaged 1D flow field downstream the diffuser exit and downstream the stage exit. Dependent on the type of return channel blade, the numerical and experimental results show a significant effect on the flow field overall and detail performance. In general, satisfactory agreement between computational fluid dynamics (CFD)-prediction and test-rig measurements was achieved regarding overall and flow-field performance. In comparison with the measurements, the CFD-calculated stage performance (efficiency and pressure rise coefficient) of all the 3D-RCH stages was slightly overpredicted. Very good agreement between CFD and measurement results was found for the static pressure distribution on the RCH wall surfaces while small CFD-deviations occur in the measured flow angle at the stage exit, dependent on the turbulence model selected.

Numerical and Experimental Investigation of Return Channel Vane Aerodynamics With 2D and 3D Vanes

2016 ◽  
Author(s):  
A. Hildebrandt ◽  
F. Schilling
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Static Pressure ◽  
Pressure Rise ◽  
Field Performance ◽  
Two Dimensional ◽  
Flow Angle ◽  
Overall Performance ◽  
Return Channel ◽  
2D And 3D

The present paper deals with the numerical and experimental investigation of the effect of return channel dimensions of a centrifugal compressor stage on the aerodynamic performance. Three different return channel stages were investigated, two stages comprising 3D (three-dimensional) return channel blades and one stage comprising (2D) two-dimensional RCH (Return Channel) vanes. The analysis was performed regarding both the investigation of overall performance (stage efficiency, RCH total pressure loss coefficient) and detailed flow field performance. For detailed experimental flow field investigation at the stage exit, six circumferentially traversed three-hole probes were positioned downstream the return channel exit in order to get two-dimensional flow field information. Additionally, static pressure wall measurements were taken at the hub and shroud pressure and suction side of the 2D and 3D return channel blades. The return channel system overall performance was calculated by measurements of the circumferentially averaged 1D flow field downstream the diffuser exit and downstream the stage exit. Dependent on the type of return channel blade, the numerical and experimental results show a significant effect on the flow field overall and detail performance. In general, satisfactory agreement between CFD-prediction and test-rig measurements was achieved regarding overall and flow field performance. In comparison with the measurements, the CFD calculated stage performance (efficiency and pressure rise coefficient) of all 3D-RCH stages was slightly over-predicted. Very good agreement between CFD and measurement results was found for the static pressure distribution on the RCH wall surfaces while small CFD-deviations occur in the measured flow angle at the stage exit, dependent on the turbulence model selected.

Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

1999 ◽  
Vol 121 (1) ◽  
pp. 119-126 ◽  
Author(s):  
E. Casartelli ◽  
A. P. Saxer ◽  
G. Gyarmathy
Keyword(s):  
Static Pressure ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Leading Edge ◽  
Inverse Design ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Characteristic Lines ◽  
Design Software

The flow field in a subsonic vaned radial diffuser of a single-stage centrifugal compressor is numerically investigated using a three-dimensional Navier–Stokes solver (TASCflow) and a two-dimensional analysis and inverse-design software package (MISES). The vane geometry is modified in the leading edge area (two-dimensional blade shaping) using MISES, without changing the diffuser throughflow characteristics. An analysis of the two-dimensional and three-dimensional effects of two redesigns on the flow in each of the diffuser subcomponents is performed in terms of static pressure recovery, total pressure loss production, and secondary flow reduction. The computed characteristic lines are compared with measurements, which confirm the improvement obtained by the leading edge redesign in terms of increased pressure rise and operating range.

scholarly journals The Model V84.3 Shot Tests: Compressor Flow Field Measurements and Evaluation

1994 ◽  
Author(s):  
M. Janssen ◽  
R. Mönig ◽  
J. Seume ◽  
H. Hönen ◽  
R. Lösch-Schloms ◽  
...  
Keyword(s):  
Flow Field ◽  
Total Pressure ◽  
Static Pressure ◽  
Pressure Rise ◽  
Full Scale ◽  
Test Facility ◽  
Design Calculation ◽  
Flow Measurements ◽  
Flow Angle ◽  
Probe Measurements

Detailed experimental investigations were carried out at the Siemens test-facility in Berlin to validate and develop further the compressor design of the Model V84.3 gas turbine and to generate a comprehensive data base for the verification of the flow calculation programs. The test facility enables Siemens to confirm the design with regard to performance and reliability in the full scale machine under full load and off-design condition. Various measuring techniques well established in the laboratory were applied to the full scale compressor to examine the flow field. Along with rather conventional 5-hole probes for measuring the flow field in the core region, miniaturized 3-hole probes were developed at the Turbomachinery Laboratory of the Technical University of Aachen, tested and finally used for the measurements of endwall boundary layer profiles and their development throughout the compressor. In addition to the probe measurements, wall static-pressure measurements, as well as probed vane measurements, were carried out. The paper briefly describes the test facility, the compressor under investigation, and the instrumentation for the flow measurements. A comparison of the 3-hole and 5-hole probe measurements is presented. The experimental results are compared with calculated results taken from a two-dimensional off-design calculation program with standard loss models. By means of the measured static-pressure rise at the casing wall and the total pressure distributions downstream of the rotor rows, a modification of the loss modeling was performed. The calculated flow field is compared to the results of the 3-hole and 5-hole probe measurements in terms of radial distributions for flow angle. Mach number and total pressure.

Numerical and Experimental Investigation on a Low-Speed Compressor Cascade With Circulation Control

2008 ◽  
Author(s):  
S. Fischer ◽  
H. Saathoff ◽  
R. Radespiel
Keyword(s):  
Wind Tunnel ◽  
Static Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Circulation Control ◽  
Two Dimensional ◽  
Compressor Cascade ◽  
Flow Topology ◽  
Wind Tunnel Tests ◽  
Low Speed

Experimental and numerical results for the flow through a stator cascade with active flow control are discussed. By blowing air through a slot close to the trailing edge of the aerofoils, the deflection angle as well as the static pressure rise in the stator are increased. The aerofoil design is representative for a 1st-stage stator geometry of a multi-stage compressor adapted for low–speed applications. To allow a reasonable transfer of the high-speed results to low-speed wind tunnel conditions, a corresponding cascade geometry was generated applying the Prandtl–Glauert analogy. With this modified cascade numerical simulations and experiments have been conducted at a Reynolds number of 5 · 105. As a reference case two-dimensional flow simulations without circulation control are considered using a Navier–Stokes solver. In the related wind tunnel tests three–dimensional conditions occur in the test rig. Nevertheless five–hole probe measurements in the wake of the blade mid section show a good agreement with the theoretical characteristics. Additional investigation along the whole blade span gives a deeper insight into the flow topology. For design conditions different blowing rates are applied. The wind tunnel tests confirm the positive benefit, which is predicted by two-dimensional calculations. The offset between simulated and measured pressure rise decreases with increasing blowing mass flows due to the reduction of the axial velocity ratio. This result is related to a redistribution of the passage flow which can only be explained in a three–dimensional analysis including the side wall influence. The benefit of the circulation control at varying blowing rates is finally characterized by the efficiency and the static pressure rise per injected energy.

The Effects of Reynolds Number on the Stall and Pre-Stall Behaviour of Compact Axial Compressors

2020 ◽  
Author(s):  
Jack Hutchings ◽  
Cesare Hall
Keyword(s):  
Reynolds Number ◽  
Flow Field ◽  
Static Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Critical Value ◽  
Rotating Stall ◽  
Secondary Flows ◽  
Transitional Flow ◽  
Number Range

Abstract Compact axial compression systems are of interest to the domestic appliance industry. The associated low Reynolds number leads to high losses compared to large-scale compressors due to a transitional flow field with large regions of separation. This paper investigates how Reynolds number variations affect the three-dimensional and unsteady flow field in a compact compressor both pre-stall and in stall. An experimental study has been conducted using a scaled-up singlestage axial compressor across a Reynolds number range of 104 to 105. Steady and unsteady casing static pressure measurements, along with rotor upstream and downstream unsteady velocity measurements, have been used to observe the rotor flow field. As the Reynolds number is reduced below a critical value, 60,000 in the case of the compressor studied, the pressure rise coefficient of the compressor decreases. The exact value of the critical Reynolds number is expected to vary with the compressor geometry. This fall off in performance corresponds to an increase in the compressor rotor secondary flows. Prior to stall, a broadband hump at around 50% of the blade passing frequency is present in the near-field casing static pressure spectra. At Reynolds numbers below the critical value, multiple equally spaced peaks also appear around the peak of the broadband hump. The spacing of these peaks has been found to be exactly equal to the measured stall cell speed once rotating stall is established. When operating in stall, the stall cell is found to increase in size and slow down as Reynolds number decreases. The measured spectra and observed flow structures show that disturbances exist prior to stall at frequencies consistent with the frequencies within stall. The size and shape of the stall cells that form are related to the extent of the three-dimensional flow field present prior to stall. Below a critical value, all of these flow features are highly sensitive to Reynolds number.

Active Control of the Corner Separation on a Highly Loaded Compressor Cascade With Periodic Nonsteady Boundary Conditions by Means of Fluidic Actuators

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Marcel Staats ◽  
Wolfgang Nitsche
Keyword(s):  
Flow Field ◽  
Static Pressure ◽  
Active Flow Control ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Compressor Cascade ◽  
Pulsed Detonation Engine ◽  
Detonation Engine ◽  
The Impact ◽  
Highly Loaded

This paper discusses the impact of a nonsteady outflow condition on the compressor stator flow that is forced through a mimic in the wake of a linear low-speed cascade to simulate the conditions that would be expected in a pulsed detonation engine. 2D/3C-PIV measurements were made to describe the flow field in the passage. Detailed wake measurements provide information about static pressure rise as well as total pressure loss. The stator profile used for the investigations is highly loaded and operates with three-dimensional flow separations under design conditions and without active flow control. It is shown that sidewall actuation helps stabilize the flow field at every phase angle and extends the operating range of the compressor stator. Furthermore, the static pressure gain can be increased by 6% with a 4% loss reduction in time-averaged data.

Active Control of the Corner Separation on a Highly Loaded Compressor Cascade With Periodic Non-Steady Boundary Conditions by Means of Fluidic Actuators

2015 ◽  
Author(s):  
Marcel Staats ◽  
Wolfgang Nitsche
Keyword(s):  
Flow Field ◽  
Static Pressure ◽  
Active Flow Control ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Side Wall ◽  
Compressor Cascade ◽  
Detonation Engine ◽  
The Impact ◽  
Highly Loaded

This contribution discusses the impact of a non-steady outflow condition on the compressor stator flow that is forced through a mimic in the wake of a linear low speed cascade to simulate the conditions that would be expected in a pulsed detonation engine. 2D/3C-PIV measurements were made to describe the flow field in the passage. Detailed wake measurements provide information about static pressure rise as well as total pressure loss. The stator profile used for the investigations is highly loaded and operates with three-dimensional flow separations under design conditions and without active flow control. It is shown that side wall actuation helps to stabilize the flow field at every phase angle and extends the operating range of the compressor stator. Furthermore, the static pressure gain can be increased by 6% with a 4% loss reduction in time averaged data.

Numerical investigations on the effect of volute casing treatment for performance augmentation in a centrifugal fan

2021 ◽  
pp. 095440622110341
Author(s):  
Manjunath L Nilugal ◽  
K Vasudeva Karanth ◽  
Madhwesh N
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Numerical Study ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Centrifugal Fan ◽  
Casing Treatment ◽  
Sliding Mesh ◽  
Optimum Configuration

This article presents the effect of volute chamfering on the performance of a forward swept centrifugal fan. The numerical analysis is performed to obtain the performance parameters such as static pressure rise coefficient and total pressure coefficient for various flow coefficients. The chamfer ratio for the volute is optimized parametrically by providing a chamfer on either side of the volute. The influence of the chamfer ratio on the three dimensional flow domain was investigated numerically. The simulation is carried out using Re-Normalisation Group (RNG) k-[Formula: see text] turbulence model. The transient simulation of the fan system is done using standard sliding mesh method available in Fluent. It is found from the analysis that, configuration with chamfer ratio of 4.4 is found be the optimum configuration in terms of better performance characteristics. On an average, this optimum configuration provides improvement of about 6.3% in static pressure rise coefficient when compared to the base model. This optimized chamfer configuration also gives a higher total pressure coefficient of about 3% validating the augmentation in static pressure rise coefficient with respect to the base model. Hence, this numerical study establishes the effectiveness of optimally providing volute chamfer on the overall performance improvement of forward bladed centrifugal fan.

Analysis of Single- and Two-Phase Flows in Turbopump Inducers

1967 ◽  
Vol 89 (4) ◽  
pp. 577-586 ◽  
Author(s):  
P. Cooper
Keyword(s):  
Equation Of State ◽  
Flow Field ◽  
Thermal Effects ◽  
Single Phase ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Recent Theory ◽  
Two Phase ◽  
Overall Efficiency

A model is developed for analytically determining pump inducer performance in both the single-phase and cavitating flow regimes. An equation of state for vaporizing flow is used in an approximate, three-dimensional analysis of the flow field. The method accounts for losses and yields internal distributions of fluid pressure, velocity, and density together with the resulting overall efficiency and pressure rise. The results of calculated performance of two sample inducers are presented. Comparison with recent theory for fluid thermal effects on suction head requirements is made with the aid of a resulting dimensionless vaporization parameter.

Study of Flow Field in Compact Spinning with Pneumatic Groove

2011 ◽  
Vol 332-334 ◽  
pp. 260-263
Author(s):  
Shi Rui Liu
Keyword(s):  
Flow Field ◽  
Negative Pressure ◽  
Static Pressure ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Compact Zone ◽  
Air Flows ◽  
Compact Spinning

In the paper the structure of the compact spinning with pneumatic groove is introduced and the characteristics of three-dimensional flow field of the compact spinning with pneumatic groove are also investigated. Results from this research confirmed that In the compact zone, the air flows to the groove and enters the inner hollow of the slot-roller through the round holes, and the air on both sides of the groove condenses to the center of it and flows to the round holes; It is beneficial to compact the fiber and make the fiber slip to the bottom of the groove with shrink shape; the velocity and negative pressure are both not homogeneous, as the round holes are not continual, and the gradient of static pressure and velocity in compact zones are also perceptible.

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