Measurement and prediction of the flow through an annular turbine cascade

by Gregory David Thomas

Publisher: Naval Postgraduate School, Publisher: Available from National Technical Information Service in Monterey, Calif, Springfield, Va

Written in English
Published: Pages: 73 Downloads: 528
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An annular turbine cascade was designed and manufactured for laser Doppler velocimetry and probe measurements in a small-scale rig. The purpose of the experiment was to determine the limitations of these measurements in a confined annulus, and to compare the experimental results with numerical predictions. Downstream probe surveys were conducted at a Reynolds number of 500000. Total pressure and temperature measurements were taken upstream of the test section, and hub static pressure was measured downstream of the cascade. A two-dimensional laser anemometer was used to obtain preliminary velocity field measurements for code validation. The two main problem areas identified were the type of seeding material used and the configuration of the optical access window. Flowfield characteristics were predicted using a three-dimensional viscous code, which were then compared to experimental measurements. The comparison showed that the numerical simulator predicted well the general features of the flow field that were measured in the experiment. Recommendations are made which would improve the mapping of the velocity field for a more complete code validation.

Edition Notes

StatementGregory D. Thomas
The Physical Object
Pagination73 p. ;
Number of Pages73
ID Numbers
Open LibraryOL25472268M

Title:laser Anemometry and Viscous Computation of the Flow Through an Annular Turbine Cascade: Studevan, Colin (LT,USN). Title:Design of a Cold-Flow Test Facility for the High-Pressure Fuel Turbopump Turbine of the Space-Shuttle Main Engine: Tapp, Eric (LT,USN). Title:Development of a Cascade Simulation of Fan-Passage Flow. linear compressor cascade at highly negative incidence angle is initially experimentally investigated. The main objective of the study is to derive the total pressure loss and outlet flow angle through the blades and use the data for the validation-calibration of a numerical solver enhancing its capability to predict highly separated flows. Updated report on Standard Configurations for the Determination of unsteady Flow Through Vibrating Axial-flow Turbomachine-Cascades Time-dependent predictions and analysis of turbine cascade data in the transonic flow region. A Unsteady Flow Visualization in a Vibrating Annular Turbine Cascade Operating in the Transonic Flow Regime. A. This thesis presents a detailed experimental investigation of the effects of inlet skew on the secondary flows and losses in a linear cascade of high turning turbine rotor blades. The blade that was used was modified from its original design to give aerodynamic similarity in the cascade flow conditions.

The numerical prediction of the flowfield through the annular turbine cascade was initiated [Ref. 8] before the blade midspan surfaces were instrumented for pressure measurements [Ref. 7]. Thus the computations, which are compared to experiment in Fig. 5, were truly a prediction. As can be seen both the suction side (lower. Goldman, L. J., "Three-Dimensional Laser Anemometry in Annular Cascades", in Advanced Methods for Cascade Testing, AGARDograph , pp. , August, Goldman, L. J., "Laser Anemometer Measurements and Computations for Transonic Flow Conditions in an Annular Cascade of High Turning Core Turbine Vanes", NASA TP, July, The Secondary Flow Loss Reduction Mechanism Investigation In A Turbine Cascade With Aerodynamic Optimization Design Nonaxisymmetric Endwall: Numerical Analysis on Fuel-Air Mixing in premixed nozzle of micro gas turbine: Investigation of Characteristics of Turbulence Boundary Layer at Mid-span in a Linear Compressor Cascade. ASME PTC Flow Measurement, Published PTC Flue and Exhaust Gas Analyses, 9 Axial-Flow Turbines Turbine Geometry Thermodynamic and Aerodynamic Theory Can-Annular and Annular Combustors Silo-Type Combustors

Accurate predictions of turbine heat transfer rates are needed to reduce the overall costs and risks In an annular blade ring, where the exit flow is not axial, the tangential flow sets up a radial at DERA Pyestock. HRST was tested as an annular cascade in (Chana, ). Later. the air flow through the thin tube was completely dissipated after passing through the honeycomb and the two-layer gauze structure, and the influence on the flow field of the turbine cascade channel was negligible. T. he calibration. of optical system must be performed to correct the perspective distortion. Inter-turbine diffusers offer the potential advantage of reducing the flow coefficient in the following stages leading to increased efficiency. The flows associated with these ducts differ from those in simple annular diffusers both as a consequence of their high-curvature S-shaped geometry and of the presence of wakes created by the upstream. The air entered the bellmouth and passed through the annulus to the rotor consisting of radial pins, either 0, or cm (1/8 or 3/16 inches) in diameter. The wakes from the pins were convected by the main flow into a turbine cascade. The rotor pins and the turbine cascade are depicted in .

Measurement and prediction of the flow through an annular turbine cascade by Gregory David Thomas Download PDF EPUB FB2

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Measurement and prediction of the flow through an annular turbine cascade Item Preview remove-circle Share or Embed This : Calhoun: The NPS Institutional Archive Theses and Dissertations Thesis Collection Measurement and prediction of the flow through an annular turbine cascade.

An annular turbine cascade was designed and manufactured for laser Doppler velocimetry and probe measurements in a small-scale rig. The purpose of the experiment was to determine the limitations of these measurements in a confined annulus, and to compare the experimental results with numerical predictions.

Downstream probe surveys were conducted at a Reynolds Author: Gregory David Thomas. Measurement and prediction of the flow through an annular turbine cascade.

Approved for public release; distribution is unlimitedAn annular turbine cascade was designed and manufactured for laser Doppler velocimetry and probe measurements in a small-scale rig.

The purpose of the experiment was to determine the limitations of these Author: Gregory David Thomas. A parallel multiblock Navier-Stokes solver with the k ‐ ω turbulence model is used to solve the unsteady flow through an annular turbine cascade, the transonic Standard Test Case 4, Test Computations are performed on a two- and three-dimensional model of the blade row with either the Euler or the Navier-Stokes flow by: An annular turbine cascade, designed for laser-Doppler velocimetry, was further modified to provide additional laser and pressure probe access.

The purpose of the research was to devise laser anemometry measurement techniques in a confined annulus and improve the ability to compare numerical predictions with experimental results.

Flowfield computations were completed using a viscous flow. The measurements were made using an ultra miniature ( mm Dia) 5-hole probe. The measurement were made on 4 planes behind and one plane in front of the trailing and leading edge of the cascade respectively. The experimental results clearly show the influence of the flow structure on the evolution of the stream wise vorticities behind the blading.

Prediction of Flutter of Turbine Blades in a Transonic Annular Cascade A parallel multiblock Navier-Stokes solver with the k-turbulence model is used to solve the unsteady flow through an annular turbine cascade, the transonic Standard Test Case 4, Test Computations are performed on a two- and three-dimensional model of the.

This paper describes the time-varying aerodynamic interaction mechanisms that have been observed within a transonic high-pressure turbine stage; these are inferred from the time-resolved behavior of the rotor exit flow field. It contains results both from an experimental program in a turbine test facility and from numerical predictions.

A study of the influence of the two adjustable parameters of the model, the transition onset location and the spot generation rate, is conducted and it is found that it can predict laminar separation bubbles, measured on a NACA airfoil. Additional results are presented for separation bubbles in an annular compressor cascade.

An accurate assessment of heat transfer rates to turbine vanes and blades is an important aspect of efficient cooling system design and component life prediction in gas turbines. Techniques have been developed at Oxford University which permit such measurements to be obtained in test rigs which provide short duration steady flow through a turbine cascade.

The temperature ratio between the gas. The schematic of the annular cascade endwall test section is shown in Fig. To ensure the flow periodicity, the annular cascade contained six vanes and five flow passages.

The flow periodicity of the annular cascade was proved to be acceptable using a multi-passage numerical model that was identical to the test section. However, EI-Batsh successfully compared the dimensionless velocities obtained by the experiment measurement and the numerical simulation using SST k-ω turbulence model in an annular cascade, and their comparison validated that, it is suitable using the SST k-ω turbulence model to simulate the fluid flow performance in annular turbine cascade.

The exit Reynolds number based on the blade axial chord is varied from × 10 5 to × 10 5 for a five blade linear cascade in a low speed wind tunnel. Unsteady wakes are produced using a spoked wheel-type wake generator upstream of the linear cascade.

Prediction of the flow through cascades of blades is fundamental to all aspects of turbomachinery aerodynamic design and analysis.

The flow through the annular cascades of blades in any. An annular turbine cascade, designed for laser-Doppler velocimetry, was further modified to provide additional laser and pressure probe access.

The purpose of the research was to devise laser anemometry measurement techniques in a confined annulus and improve the ability to compare numerical predictions with experimental results. Flow through a linear cascade of high-turning, low aspect ratio turbine blades has been measured in great detail at five planes within the cascade and two downstream in order to trace the.

The quasi-two-dimensional flow through compressor or turbine blading can be simulated by the flow through a plane CASCADE, i.e., by a row of blades having identical shapes and constant spacing along the blade height.

The cascade is used to divert a flow. Measurement and Prediction of the Flow Through an Annular Turbine Cascade r by Gregory D. Thomas Lieutenant, United States Navy B.S., Colorado School of Mines, Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN AERONAUTICAL ENGINEERING 0 from the NAVAL POSTGRADUATE SCHOOL * * June The unsteady flow field within an annular turbine rotor was investigated experimentally using an LDV system with emphasis on the influence of turbine stator wake on the rotor flow field.

Z.-H. Du's 79 research works with citations and reads, including: Study of the Water Droplets Impingement Characteristics on the S Airfoil. A parallel multiblock Navier-Stokes solver with the k-turbulence model is used to solve the unsteady flow through an annular turbine cascade, the transonic Standard Test Case 4, Test was utilised.

A model of a linear cascade and five models of annular cascades of various hub-to-tip ratios were built by means of the program GAMBIT. The flow through the cascades was simulated using a commercial CFD code, namely FLUENT.

Boundary conditions as well as the geometries of the blade row were sourced from [1]. annular turbine rotor cascade. The measurement s are carried out at the inlet, in the blade passage and at the cxit of the cascade using a fi ve-hole probe and a seven-hole probe.

The results indicate that the incoming fl ow to the rotor cascade is. Aeroelastic instability in turbomachinery is one of the severe problems limiting its performance. Of particular interest is the phenomenon of stall flutter in compressors, which occurs when blades.

The facility allows an independent variation of Reynolds and Mach numbers, providing aerodynamic and heat transfer measurements in the region of interest for gas turbine design. The mass flow rate through the cascade at NGV design conditions (exit Mach number and Reynolds number × 10 6) is 38 kg/s and the pressure-regulated test.

the annular sector cascade. Combining the strength of the annular cascade (real modeling of flow features, radial pressure gradient) it avoids excess preparation and operation costs thanks to reducing the flow channel to a sector rather than a full annulus.

Flow periodicity is thus no longer inherently present but can be achieved artificially. Fischer, Andreas, Bu¨ttner, Lars, Czarske, Ju¨rgen, Gottschall, Marcel, Mailach, Ronald, and Vogeler, Konrad. "Investigation of the Tip Clearance Flow in a Compressor Cascade Using a Novel Laser Measurement Technique With High Temporal Resolution." Proceedings of the ASME Turbo Expo: Turbine Technical Conference and Exposition.

Laser anemometry and viscous computation of the flow through an annular turbine cascade. By Joseph Derwood Spitz. Download PDF (4 MB) Abstract. Approved for public release: distribution is unlimitedAn annular turbine cascade, designed for laser-Doppler velocimetry, was further modified to provide additional laser and pressure probe access.

Figure shows the principle of ejector drilling. MWF is supplied to the inlet of the collet chuck. Then this fluid separates into two parts. The first part flows into the annular channel formed by the boring bar, called the outer tube and the inner tube.

In the drill head, MWF flows outside through the radial holes made in the drill head so that it reaches the machining zone where it cools. Flowfield characteristics were computed using a three-dimensional flow solver with the numerical plane coincident with the experimental measurement location.

An annular turbine cascade, designed for laser-Doppler velocimetry, was modified to obtain blade .When the flow is subjected to a pressure gradient, the low velocity regions in the boundary layer are affected more, resulting in vortices and other flow phenomena.

Figure Boundary layer velocity profile (Bartl ) Three commonly observed secondary flow phenomena in a turbine cascade are the.A numerical study is conducted to analyse the two-dimensional incompressible Navier-Stokes flows through the rectilinear and radial cascade of turbine blades.

The flows are turbulent and their characteristics are relevant to those of the hydraulic turbines. For the rectilinear cascade, calculations have been made for a NACA 80 series turbine blade with various angles of attack.