An Experimental Determination of Losses in a Three-Port Wave Rotor

1998 ◽  
Vol 120 (4) ◽  
pp. 833-842 ◽  
Author(s):  
J. Wilson
Keyword(s):  
Experimental Determination ◽  
Gas Turbine ◽  
Specific Power ◽  
Wave Rotor ◽  
Statistical Experiment ◽  
Wave Rotors ◽  
Flow Divider ◽  
Topping Cycle ◽  
End Wall

Wave rotors, used in a gas turbine topping cycle, offer a potential route to higher specific power and lower specific fuel consumption. In order to calculate this potential realistically, a knowledge of the loss mechanisms is required. The experiment reported here was designed as a statistical experiment to identify the losses due to finite passage opening time, friction, and leakage, using a three-port, flow divider, wave rotor cycle. Incidence loss was also found to be important. Rotors of 12 in. diameter were used, with two different lengths, 9 in. and 18 in., and two different passage widths, 0.25 in. and 0.54 in., in order to vary friction and opening time. To vary leakage, moveable end walls were provided so that the rotor to end wall gap could be adjusted. The experiment is described, and the results are presented, together with a parametric fit to the data.

scholarly journals An Experimental Determination of Losses in a 3-Port Wave Rotor

1996 ◽  
Author(s):  
Jack Wilson
Keyword(s):  
Gas Turbine ◽  
Specific Power ◽  
Wave Rotor ◽  
Statistical Experiment ◽  
Wave Rotors ◽  
Flow Divider ◽  
Wave Cycle ◽  
Topping Cycle ◽  
End Wall

Wave rotors, used in a gas turbine topping cycle, offer a potential route to higher specific power and lower specific fuel consumption. In order to exploit this potential properly, it is necessary to have some realistic means of calculating wave rotor performance, taking losses into account, so that wave rotors can be designed for good performance. This in turn requires a knowledge of the loss mechanisms. The experiment reported here was designed as a statistical experiment to identify the losses due to finite passage opening time, friction, and leakage. For simplicity, the experiment used a 3-port, flow divider, wave cycle, but the results should be applicable to other cycles. A 12” diameter rotor was used, with two different lengths, 9” and 18”, and two different passage widths, 0.25” and 0.54”, in order to vary friction and opening time. To vary leakage, moveable end-walls were provided so that the rotor to end-wall gap could be adjusted. The experiment is described, and the results are presented, together with a parametric fit to the data. The fit shows that there will be an optimum passage width for a given wave rotor, since, as the passage width increases, friction losses decrease, but opening-time losses increase, and vice-versa. Leakage losses can be made small at reasonable gap sizes.

Defining the Thermodynamic Efficiency in a Wave Rotor

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Shining Chan ◽  
Huoxing Liu ◽  
Fei Xing
Keyword(s):  
Gas Turbine ◽  
Control Volume ◽  
Thermodynamic Efficiency ◽  
Wave Rotor ◽  
Wave Rotors ◽  
Compression And Expansion ◽  
Efficiency Estimation ◽  
Parametric Analyses ◽  
Control Volumes ◽  
Thermodynamic Processes

A wave rotor enhances the performance of a gas turbine with its internal compression and expansion, yet the thermodynamic efficiency estimation has been troubling because the efficiency definition is unclear. This paper put forward three new thermodynamic efficiency definitions to overcome the trouble: the adiabatic efficiency, the weighted-pressure mixed efficiency, and the pressure pre-equilibrated efficiency. They were all derived from multistream control volumes. As a consequence, they could correct the efficiency values and make the values for compression and expansion independent. Moreover, the latter two incorporated new models of pre-equilibration inside a control volume, and modified the hypothetical “ideal” thermodynamic processes. Parametric analyses based on practical wave rotor data demonstrated that the trends of those efficiency values reflected the energy losses in wave rotors. Essentially, different thermodynamic efficiency definitions indicated different ideal thermal cycle that an optimal wave rotor can provide for a gas turbine, and they were recommended to application based on that essence.

scholarly journals Assessment of Combustion Modes for Internal Combustion Wave Rotors

1999 ◽  
Vol 121 (2) ◽  
pp. 265-271 ◽  
Author(s):  
M. R. Nalim
Keyword(s):  
Gas Turbine ◽  
Combustion Wave ◽  
Mode Selection ◽  
Internal Combustion ◽  
Combustion Mode ◽  
Wave Rotor ◽  
Turbine Engine ◽  
Reasonable Time ◽  
Wave Rotors ◽  
Combustion Modes

Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Three modes of combustion are assessed: premixed autoignition (detonation), premixed deflagration, and non-premixed autoignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The autoignition modes will require inlet temperatures in excess of 800 K for reliable ignition with most hydrocarbon fuels. Examples of combustion mode selection are presented for two engine applications.

Analysis of Aerodynamic Performance of a Microscale Radial Flow Wave-rotor for Gas Turbine Topping Cycle

2019 ◽  
Vol 139 (8) ◽  
pp. 225-237
Author(s):  
Shori Taguchi ◽  
Kohei Rikuno ◽  
Shinya Kumagai ◽  
Toshiyuki Toriyama
Keyword(s):  
Gas Turbine ◽  
Radial Flow ◽  
Aerodynamic Performance ◽  
Wave Rotor ◽  
Topping Cycle

scholarly journals Wave-Rotor-Enhanced Gas Turbine Engines

1997 ◽  
Vol 119 (2) ◽  
pp. 469-477 ◽  
Author(s):  
G. E. Welch ◽  
S. M. Jones ◽  
D. E. Paxson
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Specific Power ◽  
Inlet Temperature ◽  
Wave Rotor ◽  
Performance Levels ◽  
Turbine Engine ◽  
The Impact

The benefits of wave rotor topping in small (300- to 500-kW [400- to 700-hp] class) and intermediate (2000- to 3000-kw [3000- to 4000-hp] class) turboshaft engines, and large (350- to 450-kN [80,000- to 100,000-lbf] class) high-bypass-ratio turbofan engines are evaluated. Wave rotor performance levels are calculated using a one-dimensional design/analysis code. Baseline and wave-rotor-enhanced engine performance levels are obtained from a cycle deck in which the wave rotor is represented as a burner with pressure gain. Wave rotor topping is shown to enhance the specific fuel consumption and specific power of small- and intermediate-sized turboshaft engines significantly. The specific fuel consumption of the wave-rotor-enhanced large turbofan engine can be reduced while it operates at a significantly reduced turbine inlet temperature. The wave-rotor-enhanced engine is shown to behave off-design like a conventional engine. Discussion concerning the impact of the wave rotor/gas turbine engine integration identifies technical challenges.

scholarly journals A Numerical Investigation of the Startup Transient in a Wave Rotor

1997 ◽  
Vol 119 (3) ◽  
pp. 676-682 ◽  
Author(s):  
D. E. Paxson
Keyword(s):  
Numerical Investigation ◽  
Gas Turbine ◽  
Wave Rotor ◽  
Turbine Engine ◽  
One Dimensional ◽  
Rotor Center ◽  
Flow Through ◽  
Startup Process ◽  
Topping Cycle ◽  
Volume Models

The startup process is investigated for a hypothetical four-port wave rotor, envisioned as a topping cycle for a small gas turbine engine. The investigation is conducted numerically using a multi-passage, one-dimensional CFD based wave rotor simulation in combination with lumped volume models for the combustor, exhaust valve plenum, and rotor center cavity components. The simulation is described and several startup transients are presented which illustrate potential difficulties for the specific cycle design investigated. In particular it is observed that, prior to combustor light-off, or just after, the flow through the combustor loop is reversed from the design direction. The phenomenon is demonstrated and several possible modification techniques are discussed that avoid or overcome the problem.

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