scholarly journals Three-Dimensional Velocity Distribution between a Stator Blade Row and Unsteady Force on a Blade due to Passing Wakes

1978 ◽  
Vol 44 (388) ◽  
pp. 4157-4166
Author(s):  
Tsutomu ADACHI ◽  
Yoshinori MURAKAMI
Keyword(s):  
Velocity Distribution ◽  
Three Dimensional ◽  
Blade Row ◽  
Unsteady Force ◽  
Stator Blade

A Comparison Between the Design Point and Near-Stall Performance of an Axial Compressor

1990 ◽  
Vol 112 (1) ◽  
pp. 109-115 ◽  
Author(s):  
N. M. McDougall
Keyword(s):  
Rotor Blade ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Tip Clearance Flow ◽  
Design Point ◽  
Blade Row ◽  
Clearance Flow ◽  
Stator Blade

Detailed measurements have been made within an axial compressor operating both at design point and near stall. Rotor tip clearance was found to control the performance of the machine by influencing the flow within the rotor blade passages. This was not found to be the case in the stator blade row, where hub clearance was introduced beneath the blade tips. Although the passage flow was observed to be altered dramatically, no significant changes were apparent in the overall pressure rise or stall point. Small tip clearances in the rotor blade row resulted in the formation of corner separations at the hub, where the blade loading was highest. More representative clearances resulted in blockage at the tip due to the increased tip clearance flow. The effects that have been observed emphasize both the three-dimensional nature of the flow within compressor blade passages, and the importance of the flow in the endwall regions in determining the overall compressor performance.

scholarly journals A Three Dimensional Computational Study of Windage Heating Within an Axial Compressor Stator Well

1998 ◽  
Author(s):  
H. K. Ozturk ◽  
P. R. N. Childs ◽  
A. B. Turner ◽  
J. M. Hannis ◽  
J. R. Turner
Keyword(s):  
Flow Rate ◽  
Computational Study ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Labyrinth Seal ◽  
Leakage Flows ◽  
Temperature Boundary ◽  
Blade Row ◽  
Stator Blade ◽  
Tip Leakage Flows

Shrouded stator blades are sometimes used to prevent vibration problems, but more often they are used to eliminate blade over-tip leakage flows. A trench or recess referred to as a stator well must be provided in the rotor drum assembly in order to accommodate the stator shroud. This paper presents a computational study of the flow and windage generation within an axial compressor stator well. Windage heating levels for a three dimensional compressible solution of flow through a geometry comprising upstream and downstream stator well cavities, labyrinth seal and the stator blade row are quantified. The potential for hot fluid ejected from the upstream stator well seal into the mainstream annulus, migrating through the blade row and being re-ingested at the downstream stator well seal for further windage heating has been studied using a layered temperature boundary condition at entry to the stator row. The possible reconfiguration of detailed stator well geometry has been explored to identify options for controlling flow rate and reducing windage levels, other than controlling clearances, yielding a 9% reduction in flow rate and a 9% reduction in windage heating.

A Comparison Between the Design Point and Near Stall Performance of an Axial Compressor

1989 ◽  
Author(s):  
N. M. McDougall
Keyword(s):  
Rotor Blade ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Pressure Rise ◽  
Tip Clearance ◽  
Tip Clearance Flow ◽  
Design Point ◽  
Blade Row ◽  
Clearance Flow ◽  
Stator Blade

Detailed measurements have been made within an axial compressor operating both at design point and near stall. Rotor tip clearance was found to control the performance of the machine by influencing the flow within the rotor blade passages. This was not found to be the case in the stator blade row, where hub clearance was introduced beneath the blade tips. Although the passage flow was observed to be altered dramatically, no significant changes were apparent in the overall pressure rise or stall point. Small tip clearances in the rotor blade row resulted in the formation of corner separations at the hub, where the blade loading was highest. More representative clearances resulted in blockage at the tip due to the increased tip clearance flow. The effects which have been observed emphasize both the three dimensional nature of the flow within compressor blade passages, and the importance of the flow in the endwall regions in determining the overall compressor performance.

scholarly journals Three-Dimensional Prescribed Velocity Blade Row Design

1990 ◽  
Author(s):  
V. Molnar ◽  
F. Ridzon ◽  
V. Adame
Keyword(s):  
Surface Modification ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Blade Profile ◽  
Profile Modification ◽  
Flow Surface ◽  
Blade Row ◽  
Actual Flow ◽  
Turbomachine Blade

A method for 3D turbomachine blade row design is presented as a subsequent tasks loop. The design follows the concept of the S1 and S2 streamsurfaces. A set of S1 surfaces is used for blade profile modification and a S2 mid-surface is used for hub and casing flow surface modification. A difference between target and actual flow velocity distribution is used to control iteration procedures for succesive geometry changes of an initial (original) blade row geometry. The design subroutines are added to standard direct codes. Results for several design cases are presented and discussed.

scholarly journals The Turbine Regime of a Rear Axial Compressor Stage

1990 ◽  
Author(s):  
Václav Cyrus
Keyword(s):  
Aspect Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Compressor Stage ◽  
Flow Mechanism ◽  
Three Dimensional Flow ◽  
Low Speed ◽  
Dimensional Flow ◽  
Blade Row ◽  
Stator Blade

A detailed investigation of three-dimensional flow has been carried out in a low speed rear axial compressor stage with aspect ratio of 1 at the extreme off-design condition-turbine regime. Measurements were performed by means of both stationery and rotating pressure probes. The mechanism of flow in the rotor and stator blade row in the turbine regime is analysed. Comparison is made with flow mechanism at the design condition.

Experimental Study of Three-Dimensional Flow in an Axial Compressor Stage

1986 ◽  
Author(s):  
Vaclav Cyrus
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Loss Coefficient ◽  
Flow Coefficient ◽  
Compressor Stage ◽  
Three Dimensional Flow ◽  
High Loss ◽  
Dimensional Flow ◽  
Blade Row ◽  
Stator Blade

A detailed investigation of three-dimensional flow was carried out in a low speed axial compressor stage with aspect ratio of 2. Data were obtained over a range of flow coefficient. The origin of large high loss regions in each blade row was found by means of a diffusion factor. The loss coefficient of rotor and stator blade rows was established on the basis of both rotating and stationary pressure probes. The predicted rotor and stator loss coefficient was compared with experiment.

scholarly journals A Fast Two-Dimensional Numerical Method for the Wake Simulation of a Vertical Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 49
Author(s):  
Zheng Yuan ◽  
Jin Jiang ◽  
Jun Zang ◽  
Qihu Sheng ◽  
Ke Sun ◽  
...  
Keyword(s):  
Velocity Distribution ◽  
Numerical Method ◽  
Three Dimensional ◽  
Particle Method ◽  
Vortex Method ◽  
Vertical Axis ◽  
Two Dimensional ◽  
Vertical Axis Wind Turbine ◽  
Wake Effect ◽  
Array Design

In the array design of the vertical axis wind turbines (VAWT), the wake effect of the upstream VAWT on the downstream VAWT needs to be considered. In order to simulate the velocity distribution of a VAWT wake rapidly, a new two-dimensional numerical method is proposed, which can make the array design easier and faster. In this new approach, the finite vortex method and vortex particle method are combined to simulate the generation and evolution of the vortex, respectively, the fast multipole method (FMM) is used to accelerate the calculation. Based on a characteristic of the VAWT wake, that is, the velocity distribution can be fitted into a power-law function, a new correction model is introduced to correct the three-dimensional effect of the VAWT wake. Finally, the simulation results can be approximated to the published experimental results in the first-order. As a new numerical method to simulate the complex VAWT wake, this paper proves the feasibility of the method and makes a preliminary validation. This method is not used to simulate the complex three-dimensional turbulent evolution but to simulate the velocity distribution quickly and relatively accurately, which meets the requirement for rapid simulation in the preliminary array design.

Three-Dimensional Flows and Loss Reduction in Axial Compressors

1987 ◽  
Vol 109 (3) ◽  
pp. 354-361 ◽  
Author(s):  
Y. Dong ◽  
S. J. Gallimore ◽  
H. P. Hodson
Keyword(s):  
Three Dimensional ◽  
Axial Compressor ◽  
Axial Flow ◽  
Tracer Gas ◽  
Suction Surface ◽  
Axial Compressors ◽  
Small Clearance ◽  
Oil Flow ◽  
Stator Blade ◽  
Flow Compressor

Measurements have been performed in a low-speed high-reaction single-stage axial compressor. Data obtained within and downstream of the rotor, when correlated with the results of other investigations, provide a link between the existence of suction surface–hub corner separations, their associated loss mechanisms, and blade loading. Within the stator, it has been shown that introducing a small clearance between the stator blade and the stationary hub increases the efficiency of the stator compared to the case with no clearance. Oil flow visualizaton indicated that the leakage reduced the extensive suction surface–hub corner separation that would otherwise exist. A tracer gas experiment showed that the large radial shifts of the surface streamlines indicated by the oil flow technique were only present close to the blade. The investigation demonstrates the possible advantages of including hub clearance in axial flow compressor stator blade rows.

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