Radial-Flow Gas Turbines

A novel centrifugal gas turbine design was developed and prototype tested. The research effort consisted of the design, development, and full prototype testing of a 50 HP centrifugal gas turbine. The novelty of the centrifugal gas turbine concept is that it is based on a radial flow gas turbine consisting of a centrifugal compressor and impulse turbine mounted on the same side of a rotating wheel. The radial flow-vaned combustor is mounted on the wheel’s stationary shroud; consequently, there is no 180-degree flow turning required as in conventional radial flow gas turbines. This very simple and rugged gas turbine concept has the following major advantages: • Single rotating component (i.e., mechanically simple and compact gas turbine). • Portability. • Short axial span. • High tolerance to injection of particulate matter. • Simple construction; low manufacturing costs. This project included the conceptual design, structural and aerodynamic analysis, performance prediction modeling, detailed design, prototype fabrication, test rig instrumentation, compressor/turbine characterization, rotordynamic signature, combustor design, combustor testing, controls implementation, light-off testing, no-load testing, and performance testing of the gas turbine. Design analyses that were performed included 1-D thermodynamics, finite element structural and thermal, rotordynamic, 2-D blade path optimization, and 3-D Computational Fluid Dynamics (CFD). Testing of all individual gas turbine elements (compressor, combustor, and turbine) as well as the entire assembly was completed. Tests showed that stable gas turbine combustion was achieved up to 26,000 RPM. The gas turbine reached self-sustaining power at 21,000 RPM and 405°C firing temperature. Thus, the centrifugal gas turbine concept was demonstrated to function properly and to achieve positive power output. However, the design output power was not achieved because of combustion stability range limitations at speeds above 20,000 RPM. Maximum output power achieved was 1.4 kW at 23,000 RPM. Recommendations are provided to overcome these operational limitations in the next model centrifugal gas turbine.

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Heat Transfer From a Shrouded Rotating Disk to a Single Fluid Stream

Journal of Heat Transfer ◽

10.1115/1.3689142 ◽

1965 ◽

Vol 87 (4) ◽

pp. 485-492 ◽

Cited By ~ 7

Author(s):

J. W. Mitchell ◽

D. E. Metzger

Keyword(s):

Heat Transfer ◽

Gas Turbines ◽

Radial Flow ◽

Rotating Disk ◽

Test Facility ◽

Algebraic Expression ◽

Fluid Stream ◽

Model Study ◽

Transfer Behavior ◽

Initial Results

This paper presents the initial results of a model study to determine the heat-transfer characteristics of radial-flow gas turbines. A test facility was constructed and several unconventional experimental techniques were developed for use in the facility. An idealized model consisting of a shrouded rotating disk with a single radially inward airflow was studied. The flow pattern and heat-transfer behavior were analytically and experimentally determined. The experimentally determined heat transfer is correlated by an algebraic expression over the range of nondimensional parameters characteristic of radial-flow gas-turbine operation.

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Enhanced Gas Turbine Performance Simulation Using CFD Modules in a 2D Representation of the Low-Pressure System for a High Bypass Turbofan

Volume 4: Cycle Innovations; Electric Power; Industrial and Cogeneration; Manufacturing Materials and Metallurgy ◽

10.1115/gt2006-90440 ◽

2006 ◽

Author(s):

Friederike C. Mund ◽

Georgios Doulgeris ◽

Pericles Pilidis

Keyword(s):

Gas Turbines ◽

Radial Flow ◽

Design Procedure ◽

Pressure System ◽

Performance Simulation ◽

Turbine Performance ◽

Combined Use ◽

Numerical Effort ◽

Low Pressure System ◽

Typical Component

The improvement of performance simulation for gas turbines has been approached in very different ways. In particular for high bypass turbofans, efforts have been made to investigate radial flow distributions. The aim of the presented study was to combine a conventional characteristics based performance code using a 2d representation of the fan with 2d representations of the adjoining intake and bypass system. Computational Fluid Dynamics was the chosen tool to generate modules for the intake, bypass duct and bypass nozzle. This approach required geometry data. A design procedure to generate these components in an axi-symmetric meridional fashion and the numerical requirements for the CFD modules were developed. Typical component performances were predicted and the combined use of CFD and the performance code showed that in terms of performance, the inclusion of intake and bypass losses and the radial inlet distribution was worth considering. In particular however, the required numerical effort was significant.

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Axial Flow and Radial Flow Gas Turbines

Turbomachinery ◽

10.1201/9780203911600-14 ◽

2003 ◽

pp. 310-350

Keyword(s):

Gas Turbines ◽

Radial Flow ◽

Axial Flow

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Heat Transfer From a Shrouded Rotating Disk With Film Cooling

Journal of Heat Transfer ◽

10.1115/1.3691458 ◽

1966 ◽

Vol 88 (1) ◽

pp. 140-146 ◽

Cited By ~ 3

Author(s):

D. E. Metzger ◽

J. W. Mitchell

Keyword(s):

Heat Transfer ◽

Film Cooling ◽

Gas Turbines ◽

Radial Flow ◽

Rotating Disk ◽

Operating Conditions ◽

Main Stream ◽

Cooling Method ◽

Model Study ◽

Transfer Behavior

A study of the cooling effect of secondary fluid injection on the heat transfer between a shrouded rotating disk and a radially inward main flow stream is presented. The investigation is intended as a model study of film-cooled, radial-flow gas turbines. The film-cooling method is reviewed, and the nondimensional parameters governing the heat transfer are obtained. Experimental results, covering the range of radial-flow, gas-turbine operating conditions, were obtained from a film-heated, rotating-disk facility. The heat-transfer behavior of the main stream only was determined separately, and the film-cooling results are presented as ratios of the heat transfer obtained with film cooling to the heat transfer obtained with only the single radial inflow.

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