Paper 6: A Rotating Pressure Transmission System for Turbo-Machinery Experiments

1967 ◽  
Vol 182 (8) ◽  
pp. 69-75
Author(s):  
M. G. Hodskinson
Keyword(s):  
Experimental Investigation ◽  
Transmission System ◽  
Centrifugal Impeller ◽  
Blade Surface ◽  
Pressure Reading ◽  
Isentropic Flow ◽  
Rotating Blade ◽  
Test Speed ◽  
Pressure Transmission ◽  
Surface Measurements

Experimental investigation of air flow in rotating blade rows is widely regarded as desirable, but is rendered difficult in practice because of high rotational speeds and the large number of pressure tappings required. The design and operation of a system using the Scanivalve and able to transmit pressures from a rotor running at 8000 rev/min is described in this paper. Some experience in the use of the system with blade surface measurements on a small (8-in diameter) centrifugal impeller is discussed. Attention is paid to sources of error in pressure readings, including the rotating head correction to convert the transmitted pressure reading into actual pressure at the point of measurement. Theoretical relative velocities in the impeller have also been obtained with Algol computer programmes for isentropic flow in the axi-symmetric and blade-to-blade directions. A comparison is made between experimental and theoretical relative velocities in the impeller in which the flow is essentially incompressible at the test speed. It is concluded that flow separation occurs early in this particular impeller channel. On the evidence of the results obtained so far, some further uses and developments of the pressure transmission system are discussed.

Effects of Rotation on Blade Surface Heat Transfer: An Experimental Investigation

1997 ◽  
Author(s):  
Roger W. Moss ◽  
Roger W. Ainsworth ◽  
Tom Garside
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Experimental Investigation ◽  
Turbine Blade ◽  
Time History ◽  
Surface Heat ◽  
Blade Surface ◽  
Surface Heat Transfer ◽  
Effects Of Rotation ◽  
Wake Passing

Measurements of turbine blade surface heat transfer in a transient rotor facility are compared with predictions and equivalent cascade data. The rotating measurements involved both forwards and reverse rotation (wake free) experiments. The use of thin-film gauges in the Oxford Rotor Facility provides both time-mean heat transfer levels and the unsteady time history. The time-mean level is not significantly affected by turbulence in the wake; this contrasts with the cascade response to freestream turbulence and simulated wake passing. Heat transfer predictions show the extent to which such phenomena are successfully modelled by a time-steady code. The accurate prediction of transition is seen to be crucial if useful predictions are to be obtained.

Numerical Simulation of Icing on the Rotating Blade

2015 ◽  
Author(s):  
Wei Dong ◽  
JianJun Zhu ◽  
Rui Wang ◽  
Yong Chen
Keyword(s):  
Collection Efficiency ◽  
Numerical Study ◽  
High Fidelity ◽  
Ice Accretion ◽  
Blade Surface ◽  
Physical Processes ◽  
Ansys Fluent ◽  
Rotating Blade ◽  
Process Simulations ◽  
Ice Shapes

The physical processes involved in ice accretion on the rotating blade are complex. It is important to develop high fidelity numerical method and simulate the icing process on the blade under icing conditions. This paper presents a numerical study on the icing process on the rotating blade. The flow field around the blade is obtained using ANSYS FLUENT. The trajectories of supercooled water droplets and the collection efficiency are calculated by Eulerian approach. Heat and mass balance on the rotating blade surface is taken into account in icing process simulations. The NASA Rotor 67 blade is chosen as the computational model. The collection efficiency on the blade surface is computed and the impingement characteristics are analyzed. The 3D icing accretion on Rotor 67 blade is predicted at design point. The ice shapes of accretion time of 5s, 10s and 15s are simulated and the ice shapes at different span positions of the rotating blade are compared.

The Laminar Boundary Layer on a Rotating Circular Arc Blade

1966 ◽  
Vol 88 (1) ◽  
pp. 111-120
Author(s):  
R. M. Halleen ◽  
J. P. Johnston ◽  
W. C. Reynolds
Keyword(s):  
Boundary Layer ◽  
Laminar Boundary Layer ◽  
Perturbation Technique ◽  
Approximate Solutions ◽  
Boundary Layer Separation ◽  
Primary Objective ◽  
Centrifugal Impeller ◽  
Pressure Gradients ◽  
Boundary Layer Problem ◽  
Rotating Blade

The primary objective was to develop an exact solution to the simplest possible laminar boundary-layer problem for a curved rotating blade. It was formulated initially so that the results might be used to illuminate some of the characteristics of boundary-layer behavior on centrifugal impeller blades. The solution was obtained by a perturbation technique and the results compared to existing approximate solutions and related exact solutions. A primary result shows that rotation itself may induce laminar boundary-layer separation on a blade trailing face in the absence of free-stream, longitudinal adverse pressure gradients. This result is then interpreted to show that such a separation may become important for impellers of low ReD = uˆtD/ν; i.e., when ReD ≤ 900.

scholarly journals Unsteady Pressure Measurements in a Rotating Centrifugal Impeller

1992 ◽  
Author(s):  
G. Roth
Keyword(s):  
Surface Pressure ◽  
Suction Side ◽  
Rotating Stall ◽  
Centrifugal Impeller ◽  
Pressure Measurements ◽  
Blade Surface ◽  
Pressure Transducers ◽  
Engine Order ◽  
Analysis Technique ◽  
Stable Operating

The design of a shrouded radial test impeller which enables the application of miniature pressure transducers inside the blades is presented. An explanation of the measurement and analysis technique is given. The results of suction side blade surface pressure measurements at several points of a performance line are presented. Two different types of diffuser rotating stall were detected. The pressure behaviour at impeller stall and surge inception is demonstrated. Furthermore, the periodic engine order blade surface pressure signals at a stable operating point are shown.

Aerodynamic Excitation and Forced Response of Centrifugal Compressor Impeller in Inlet Distortion

2015 ◽  
Author(s):  
Yixiong Liu ◽  
Dazhong Lao ◽  
Ce Yang ◽  
Leilei Wang ◽  
Du Li
Keyword(s):  
Pressure Fluctuation ◽  
Forced Response ◽  
Centrifugal Impeller ◽  
Aerodynamic Load ◽  
Individual Response ◽  
Blade Surface ◽  
Transient Pressure ◽  
Fe Method ◽  
Inlet Distortion ◽  
Compressor Impeller

The forced response of the turbomachinery blade originates from unsteady fluid structure interactions due to the fluctuating aerodynamic load. As one of the primary unsteady issues, inlet distortion flow breaks the uniformity of airflow through the compressor channel which deteriorates the aerodynamic performance of the compressor and intensifies the pressure fluctuation on the blade surface. The work presented here arms to investigate the forced response of a centrifugal impeller induced by compressor inlet distortion. For this purpose, the unsteady flow computation was carried out to provide the temporal evolution of the distorted flow through the compressor and also to quantify the aerodynamic loads acting on the compressor blade due to inlet distortion flow compared with uniform inlet. Meanwhile, the experimental measurement was performed to obtain the transient pressure fluctuation on the blade surface and to validate the accuracy of numeric calculation. The forced response of the compressor impeller based on unsteady excitation was simulated in a finite element (FE) method to gain insight into vibration characteristic of each blade. Time-resolved blade pressure showed the drastic load fluctuation caused by distorted flow mainly located in the blade leading edge region due to the inlet airflow variation. Towards the impeller forced vibration, each blade shows individual response amplitude due to the phase angle difference among the blades. The effect of inlet distortion on the forced response of impeller increases significantly compared with that of the uniform inlet flow.

Experimental investigation of dispersion management for an 8 x 10-Gb/s WDM transmission system over nonzero dispersion-shifted fiber

1999 ◽  
Vol 11 (8) ◽  
pp. 1045-1047 ◽  
Author(s):  
A. Bertaina ◽  
S. Bigo ◽  
C. Francia ◽  
S. Gauchard ◽  
J.-P. Hamaide ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Transmission System ◽  
Dispersion Management ◽  
Wdm Transmission

Comparison of the HTTT Reheat-Gas-Turbine Combined Cycle With the HTTT Nonreheat Gas-Turbine Combined Cycle

1982 ◽  
Vol 104 (1) ◽  
pp. 129-142
Author(s):  
I. G. Rice ◽  
P. E. Jenkins
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Department Of Energy ◽  
Growth Potential ◽  
United States Department ◽  
Blade Surface ◽  
Rotating Blade ◽  
Cycle Efficiency ◽  
Analytical Approaches

High-temperature turbine technology (HTTT) when applied to the reheat-gas-turbine combined cycle (RHGT/CC) offers distinct advantages over the presently contemplated United States Department of Energy (DOE) HTTT simple-cycle gas-turbine combined cycle (SCGT/CC) being developed for gaseous fuel derived from coal. Specific improvements are: 1) higher combined-cycle efficiency, 2) higher specific output per unit of air flow, 3) less critical high-temperature nozzle-vane and rotating-blade surface area to be cooled, 4) less strategic high temperature metal material to be used, and 5) less overall cycle-cooling degradation allowing growth potential. New cooling techniques employing steam are required to accomplish these projections which necessitates advanced research and development and presently unavailable mathematical analytical approaches.

Sign in / Sign up

Export Citation Format

Share Document