Wave Turbine Analysis Tool Development

Wave Turbine Analysis Tool Development PDF

Author: Gerard E. Welch

Publisher:

Published: 1998

Total Pages: 20

ISBN-13:

DOWNLOAD EBOOK →

A quasi-one-dimensional (Q-1-D) computational fluid dynamic solver, previously developed and validated for pressure-exchanger wave rotors, is extended in the present work to include the blade forces of power producing wave rotors (i.e., wave turbines). The accuracy of the single-passage Q-1-D solver is assessed relative to two two-dimensional solvers: a single-passage code and a multi-block stator/rotor/stator code. Comparisons of computed results for inviscid, steady and unsteady flows in passage geometries typical of wave rotors reveal that the blade force model is accurate and that the correlation (effective stress and heat flux) terms of the Q-1-D passage-averaged formulation can be neglected. The ends of the rotor passages pose particular challenges to Q-1-D formulations because the flow there must at times deviate significantly from the mean camber line angle to match the port flow fields. This problem is most acute during the opening and closing of the rotor passages. An example sub-model is developed to account for the deviation between the flow departure angle and the mean camber line exit angle that occurs as an inviscid flow decelerates to meet a uniform pressure boundary. Comparisons of results from four-port wave turbine simulations reveal that the Q-1-D solver currently overpredicts wave turbine performance levels and highlight the need to devote future effort to the boundary conditions and sub-models of the Q-1-D solver.

Wave-Rotor-Enhanced Gas Turbine Engine Demonstrator

Wave-Rotor-Enhanced Gas Turbine Engine Demonstrator PDF

Author:

Publisher:

Published: 1999

Total Pages: 18

ISBN-13:

DOWNLOAD EBOOK →

The U.S. Army Research Laboratory, NASA Glenn Research Center, and Rolls-Royce Allison are working collaboratively to demonstrate the benefits and viability of a wave-rotor-topped gas turbine engine. The self-cooled wave rotor is predicted to increase the engine overall pressure ratio and peak temperature by 300% and 25 to 30%, respectively, providing substantial improvements in engine efficiency and specific power. Such performance improvements would significantly reduce engine emissions and the fuel logistics trails of armed forces. Progress towards a planned demonstration of a wave-rotor-topped Rolls-Royce Allison model 250 engine has included completion of the preliminary design and layout of the engine, the aerodynamic design of the wave rotor component and prediction of its aerodynamic performance characteristics in on- and off-design operation and during transients, and the aerodynamic design of transition ducts between the wave rotor and the high pressure turbine. The topping cycle increases the burner entry temperature and poses a design challenge to be met in the development of the demonstrator engine.

Passage-Averaged Description of Wave Rotor Flow

Passage-Averaged Description of Wave Rotor Flow PDF

Author: Gerard E. Welch

Publisher:

Published: 1997

Total Pages: 14

ISBN-13:

DOWNLOAD EBOOK →

The unsteady flow within wave rotor passages is influenced by the rotor blade, hub, and tip shroud surface profiles. By averaging from hub to shroud and from blade to blade, a reduced set of the governing equations is obtained that is appropriate for design studies and parametric analyses. The application of these equations requires closure models for force integrals and for correlation terms that arise when the density averages of products of the flow field variables are expanded in terms of products of the density-averaged variables. The force integrals and the correlation terms depend on the instantaneous pitchwise and spanwise flow field distributions established by unsteadiness relative to the rotor, flow turning induced by blade, hub, and tip-shroud profiling, and rotation. Two approaches to model the force integrals are described. The influence of relative unsteadiness and flow turning on the correlation terms is discussed by considering the propagation of gas dynamic waves in rotor passages defined by uncambered, staggered blades and by unstaggered, cambered blades.

Wave Rotor Demonstrator Engine Assessment

Wave Rotor Demonstrator Engine Assessment PDF

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-07-17

Total Pages: 76

ISBN-13: 9781722868215

DOWNLOAD EBOOK →

The objective of the program was to determine a wave rotor demonstrator engine concept using the Allison 250 series engine. The results of the NASA LERC wave rotor effort were used as a basis for the wave rotor design. A wave rotor topped gas turbine engine was identified which incorporates five basic requirements of a successful demonstrator engine. Predicted performance maps of the wave rotor cycle were used along with maps of existing gas turbine hardware in a design point study. The effects of wave rotor topping on the engine cycle and the subsequent need to rematch compressor and turbine sections in the topped engine were addressed. Comparison of performance of the resulting engine is made on the basis of wave rotor topped engine versus an appropriate baseline engine using common shaft compressor hardware. The topped engine design clearly demonstrates an impressive improvement in shaft horsepower (+11.4%) and SFC (-22%). Off design part power engine performance for the wave rotor topped engine was similarly improved including that at engine idle conditions. Operation of the engine at off design was closely examined with wave rotor operation at less than design burner outlet temperatures and rotor speeds. Challenges identified in the development of a demonstrator engine are discussed. A preliminary design was made of the demonstrator engine including wave rotor to engine transition ducts. Program cost and schedule for a wave rotor demonstrator engine fabrication and test program were developed. Snyder, Philip H. Glenn Research Center...

Lanterna Rally - Theme by Grace Themes