A comparison between numerically modelled and experimentally measured loss mechanisms in wave rotors

Paxson, Daniel E.

doi:10.2514/6.1993-2522

Cited by 22 publications

(13 citation statements)

References 3 publications

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“…4 This model accounts for heat transfer between the passage walls and the internal flow using a semi-empirical correlation analogous to that used to model the momentum transport to the walls (friction). 12 The effect of friction on wave-rotor performance predicted by the model has been experimentally verified. 6 The model also includes heat transfer between the walls and the housing cavities fed by Ieakage.lt is noted that the wall temperature estimates are based on the assumption of radial heat transfer and conduction only, on the top and bottom walls ofthe passage.…”

Section: Rotor Coolingmentioning

confidence: 91%

Modified Through-Flow Wave-Rotor Cycle with Combustor-Bypass Ducts

Paxson

Nalim

1999

Journal of Propulsion and Power

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A wave-rotor cycle is described that avoids the inherent problem of combustor exhaust gas recirculation (EGR) found in four-port, through-flow (uniflow) pressure-gain wave-rotor cycles currently under consideration for topping gas-turbine engines. The recirculated hot gas is eliminated by the judicious placement of a bypass duct that transfers gas from one end of the rotor to the other. The resulting cycle, when analyzed numerically, yields a mean absolute temperature for the rotor that is 18% below the already impressive value (approximately the turbine inlet temperature) predicted for the conventional four-port cycle. The absolute temperature of the gas leading to the combustor is also reduced from the conventional design by 17%. The overall design-point pressure ratio of this new bypass cycle is approximately the same as the conventional cycle. This paper will describe the EGR problem and the bypass-cycle solution, including relevant wave diagrams. Performance estimates of design and off-design operation of a specific wave rotor will be presented. The results were obtained using a one-dimensional numerical simulation and design code.

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Section: Rotor Coolingmentioning

confidence: 91%

Modified Through-Flow Wave-Rotor Cycle with Combustor-Bypass Ducts

Paxson

Nalim

1999

Journal of Propulsion and Power

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“…Applied to the case of an aircraft flying at Mach 0.8 , they have shown that a wave-rotor topped engine may gain 1…2% in efficiency and 10…16% in specific power compared to a simple jet engine with the same overall pressure ratio and turbine inlet temperature. Paxson also has developed a one-dimensional design model to calculate off-design wave rotor performance 19 and has verified it using experimental data. The model solves the unsteady viscous flow field in an axial passage for time-constant inlet and outlet port conditions, while accounting for losses due to gradual passage opening and closing, viscous and heat transfer effects, leakage, and nonuniform port flow field mixing.…”

Section: History Of Wave Rotorsmentioning

confidence: 99%

Performance Investigation of Small Gas Turbine Engines Topped with Wave Rotors

Akbari

Müller

2003

39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

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A performance analysis is performed for a small turbojet engine topped with various wave rotor cycles. Five different advantageous implementation cases for a four-port wave rotor into the given baseline engine are studied. The compressor and turbine pressure ratios, and the turbine inlet temperatures vary in the thermodynamic calculations according to the anticipated design objectives of the five considered cases. Advantages and disadvantages are outlined. Comparison between the theoretic performance results of wave-rotor-topped engines and the baseline engine shows a significant performance enhancement for almost all the cases studied. The highest gain is obtained for the case in which the topped engine operates with the same turbine pressure ratio, inlet temperature and the same physical compressor like that of the baseline engine. A general design map is generated showing the design space and optima for the baseline and topped engines. INTRODUCTIONGas turbines are typical power sources used in a wide size range for propulsion and power generation systems. Recently, there has been considerable interest in the research, development, and application of small gas turbines yielding high power density and enabling low-cost air vehicles. However, resulting from the smaller size, their efficiency and pressure ratio, hence specific work, are mostly lower than those of the large scale systems. Therefore, innovations are required to attractively enhance their performance.

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“…The working fluid is assumed to be a calorically perfect gas. The details of this code have been described in previous publications [5][6][7] and will not be presented here. Although several loss mechanisms are accounted for, those of interest here result from the effects of viscosity, gradual passage opening (so called finite opening time), and mixing of non-uniform velocity profiles in the exhaust port 4.…”

Section: Cfd Wa Vb Rotor Modelmentioning

confidence: 99%

“…What is needed then, is a realistic calculation of wave rotor performance, including the major losses, which can be used to examine variations in geometry to find optimum performance. A suitable, one-dimensional, computational fluid dynamics (CFD) code has been written [5,6], and was used for this report. The code has been validated against experiment [7], and gives good agreement with the experimental results of Klapproth et al [1], and Kentfield [8].…”

Section: Introductionmentioning

confidence: 99%

Optimization of Wave Rotors for Use as Gas Turbine Engine Topping Cycles

Wilson¹,

Paxson

1995

SAE Technical Paper Series

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Use of a wave rotor as a topping cycle for a gas turbine engine can improve specific power and reduce specific fuel consumption. Maximum improvement requires the wave rotor to be optimized for best performance at the mass flow of the engine. The optimization is a trade-off between losses due to friction and passage opening time, and rotational effects. An experimentally validated, one-dimensional CFD code, which includes these effects, has been used to calculate wave rotor performance, and find the optimum configuration. The technique is described, and results given for wave rotors sized for engines with sea level mass flows of 4, 26, and 400 lb/sec.

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A comparison between numerically modelled and experimentally measured loss mechanisms in wave rotors

Cited by 22 publications

References 3 publications

Modified Through-Flow Wave-Rotor Cycle with Combustor-Bypass Ducts

Modified Through-Flow Wave-Rotor Cycle with Combustor-Bypass Ducts

Performance Investigation of Small Gas Turbine Engines Topped with Wave Rotors

Optimization of Wave Rotors for Use as Gas Turbine Engine Topping Cycles

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