Author: Publisher: ISBN: Category : Languages : en Pages : 18
Book Description
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.
Author: National Aeronautics and Space Adm Nasa Publisher: Independently Published ISBN: 9781724013927 Category : Science Languages : en Pages : 30
Book Description
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. Welch, Gerard E. and Paxson, Daniel E. and Wilson, Jack and Synder, Philip H. Glenn Research Center NASA/TM-1999-209459, NAS 1.15:209459, ARL-TR-2113, E-11958
Author: Gerard E. Welch Publisher: ISBN: Category : Languages : en Pages : 20
Book Description
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.
Author: Gerard E. Welch Publisher: ISBN: Category : Languages : en Pages : 14
Book Description
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.
Author: Wade H. Shafer Publisher: Springer Science & Business Media ISBN: 1461528321 Category : Science Languages : en Pages : 350
Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 36 (thesis year 1991) a total of 11,024 thesis titles from 23 Canadian and 161 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 36 reports theses submitted in 1991, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Author: 
Author: Gregory P. Mathis
Author: Gerard E. Welch
Author: Jack Wilson
Author: National Aeronautics and Space Adm Nasa
Author: Pezhman Akbari
Author: 
Author: Gerard E. Welch
Author: Gerard E. Welch
Author: Wade H. Shafer