T63 Turbine Response to Rotating Detonation Combustor Exhaust Flow

2018 ◽  
Author(s):  
Andrew Naples ◽  
Ryan Battelle ◽  
John Hoke ◽  
Fred Schauer
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Temperature Pattern ◽  
Hydrogen Fuel ◽  
Fuel Temperature ◽  
Pressure Transducers ◽  
Turbine Efficiency ◽  
Turbine Component ◽  
Component Efficiency ◽  
Rotating Detonation

This paper describes testing an axial turbine response when driven by a Rotating Detonation Combustor (RDC). A T63 (C20-250) gas turbine is modified by replacing the combustor with a RDC. The stator vanes of the T63 are heavily instrumented for measurement of flow enthalpy and pressure. The engine is run at multiple power levels with the stock combustor using JetA and hydrogen fuel. The engine is then modified to have an open loop configuration, and is run with both the RDC and the stock combustor hardware with hydrogen fuel. Temperature pattern factor, flow unsteadiness, and turbine component efficiency are measured for all setups. High speed pressure transducers show substantially higher unsteadiness generated by the RDC than the conventional combustor. RDC turbine component efficiencies are compared to the conventional combustor. Results suggest that RDC unsteadiness does not significantly impact turbine efficiency.

T63 Turbine Response to Rotating Detonation Combustor Exhaust Flow

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Andrew Naples ◽  
John Hoke ◽  
Ryan Battelle ◽  
Fred Schauer
Keyword(s):  
High Speed ◽  
Open Loop ◽  
Temperature Pattern ◽  
Hydrogen Fuel ◽  
Fuel Temperature ◽  
Pressure Transducers ◽  
Turbine Efficiency ◽  
Turbine Component ◽  
Component Efficiency ◽  
Rotating Detonation

This paper describes testing an axial turbine response when driven by a rotating detonation combustor (RDC). A T63 (C20-250) gas turbine is modified by replacing the combustor with a RDC. The stator vanes of the T63 are heavily instrumented for the measurement of flow enthalpy and pressure. The engine is run at multiple power levels with the stock combustor using JetA and hydrogen fuel. The engine is then modified to have an open loop configuration and is run with both the RDC and the stock combustor hardware with hydrogen fuel. Temperature pattern factor, flow unsteadiness, and turbine component efficiency are measured for all setups. High-speed pressure transducers show substantially higher unsteadiness generated by the RDC than the conventional combustor. RDC turbine component efficiencies are compared to the conventional combustor. Results suggest that RDC unsteadiness does not significantly impact turbine efficiency.

Stall Inception in a High Speed Centrifugal Compressor During Speed Transients

2017 ◽  
Author(s):  
Fangyuan Lou ◽  
John C. Fabian ◽  
Nicole L. Key
Keyword(s):  
Heat Transfer ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Flow Instability ◽  
Leading Edge ◽  
Fast Response ◽  
Rotating Stall ◽  
Transient Performance ◽  
Stall Inception ◽  
Pressure Transducers

The inception and evolution of rotating stall in a high-speed centrifugal compressor are characterized during speed transients. Experiments were performed in the Single Stage Centrifugal Compressor (SSCC) facility at Purdue University and include speed transients from sub-idle to full speed at different throttle settings while collecting transient performance data. Results show a substantial difference in the compressor transient performance for accelerations versus decelerations. This difference is associated with the heat transfer between the flow and the hardware. The heat transfer from the hardware to the flow during the decelerations locates the compressor operating condition closer to the surge line and results in a significant reduction in surge margin during decelerations. Additionally, data were acquired from fast-response pressure transducers along the impeller shroud, in the vaneless space, and along the diffuser passages. Two different patterns of flow instabilities, including mild surge and short-length-scale rotating stall, are observed during the decelerations. The instability starts with a small pressure perturbation at the impeller leading edge and quickly develops into a single-lobe rotating stall burst. The stall cell propagates in the direction opposite of impeller rotation at approximately one third of the rotor speed. The rotating stall bursts are observed in both the impeller and diffuser, with the largest magnitudes near the diffuser throat. Furthermore, the flow instability develops into a continuous high frequency stall and remains in the fully developed stall condition.

scholarly journals The Modelling, Simulation and FPGA-Based Implementation for Stepper Motor Wide Range Speed Closed-Loop Drive System Design

Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Closed Loop ◽  
Open Loop ◽  
Drive System ◽  
Stepper Motor ◽  
Motor Drive ◽  
Digital Controllers ◽  
Loop Control ◽  
Wide Range

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.

scholarly journals The Design and Evaluation of a High Pressure Ratio Radial Turbine

1992 ◽  
Author(s):  
K. R. Pullen ◽  
N. C. Baines ◽  
S. H. Hill
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Pressure Ratio ◽  
Performance Measurements ◽  
Turbine Engine ◽  
High Pressure Ratio ◽  
Turbine Efficiency ◽  
Wide Range ◽  
Dimensional Parameters ◽  
Very High

A single stage, high speed, high pressure ratio radial inflow turbine was designed for a single shaft gas turbine engine in the 200 kW power range. A model turbine has been tested in a cold rig facility with correct simulation of the important non-dimensional parameters. Performance measurements over a wide range of operation were made, together with extensive volute and exhaust traverses, so that gas velocities and incidence and deviation angles could be deduced. The turbine efficiency was lower than expected at all but the lowest speed. The rotor incidence and exit swirl angles, as obtained from the rig test data, were very similar to the design assumptions. However, evidence was found of a region of separation in the nozzle vane passages, presumably caused by a very high curvature in the endwall just upstream of the vane leading edges. The effects of such a separation are shown to be consistent with the observed performance.

Modeling and Analysis for Thermal Control of Spindles for Reconfigurable Machines

2001 ◽  
Author(s):  
Jeffrey L. Stein ◽  
John E. Harder
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Thermal Control ◽  
Open Loop ◽  
Limiting Factor ◽  
Process Conditions ◽  
Bearing Load ◽  
Bearing Loads

Abstract Control of thermally induced bearing loads remains an important but unsolved problem for precision, high-speed, metal cutting, machining spindles. Spindle dynamic performance, as well as spindle life, depends on bearing loads. Because these loads can change drastically with a change in process conditions, poor spindle dynamic performance, and dramatically reduced bearing life can result. The purpose of this paper is to evaluate the feasibility of controlling bearing loads by controlling the heat generated by a thermal actuator placed around the housing of the spindle. A mathematical model of the open loop response of a laboratory prototype spindle is developed and validated. The model is then used to evaluate the closed loop performance. The results show that closed loop control of the bearing load is achievable in steady state and under bandwidth limited transient conditions. The proposed system has reasonable command authority when additional heat is required, however, it is possible for the system to lose control when the heater is required to “provide” negative heat. This situation can be mitigated by proper choice of initial preload. As expected, measurement noise limits the control gain but is not a limiting factor. More open loop tests are suggested to validate the model under a broader set of conditions. In addition, closed loop validation is suggested. However, based on results obtained it appears bearing load control is achievable by controlling the thermal field around the spindle.

Mechanically Amplified Piezoelectric Microactuators for Laminar-Turbulent Transition Control on Airfoils

2009 ◽  
Vol 6 (4) ◽  
pp. 211-218 ◽  
Author(s):  
C. Bolzmacher ◽  
X. Riedl ◽  
J. Leuckert ◽  
M. Engert ◽  
K. Bauer ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
High Speed ◽  
Leading Edge ◽  
Transition Process ◽  
Open Loop ◽  
Film Sensor ◽  
Transition Control ◽  
Transitional Boundary Layer ◽  
Tollmien Schlichting

Drag reduction on airfoils using arrays of micro-actuators is one application of so-called Aero-MEMS. These microactuators interact with TS instabilities (Tollmien-Schlichting waves) inside a transitional boundary layer by superimposing artificially generated counterwaves in order to delay the transition process. These actuators need to exhibit a relatively large stroke at relatively high operational frequencies when operated at high Mach numbers. For this purpose, a novel micromachined mechanical amplification unit for increasing the stroke of piezoelectric microactuators up to high frequencies is proposed. The mechanical lever is provided by a sliced nickel titanium membrane. In this work, the actuator is explained in detail and wind tunnel experiments are carried out to investigate the effect of this mechanically amplified piezoelectric microactuator on thin transitional boundary layers. The experiments have been carried out in the transonic wind tunnel facility of the Berlin University of Technology on an unswept test wing with an NACA 0004 leading edge. The effectiveness of the actuator for flow control applications is determined in an open-loop setup consisting of one actuator having a relevant spanwise extension and a microstructured hot film sensor array located downstream. The aerodynamic results at Mach 0.33 are presented and discussed. It is shown that the actuator influences TS wave specific frequencies between 2.5 kHz and 7.4 kHz. The actuator amplitude is large enough to influence a transitional boundary layer significantly without bypassing the natural transition process which makes this type of micromachined actuator a candidate for high speed TS-control.

Active Stabilization of Rotating Stall in a Three-Stage Axial Compressor

1993 ◽  
Author(s):  
Joel M. Haynes ◽  
Gavin J. Hendricks ◽  
Alan H. Epstein
Keyword(s):  
High Speed ◽  
Travelling Waves ◽  
Axial Compressor ◽  
Open Loop ◽  
Rotating Stall ◽  
Forced Response ◽  
Flow Coefficient ◽  
Design Parameters ◽  
Time Lags ◽  
Active Stabilization

A three-stage, low speed axial research compressor has been actively stabilized by damping low amplitude circumferentially travelling waves which can grow into rotating stall. Using a circumferential array of hot wire sensors, and an array of high speed individually positioned control vanes as the actuator, the first and second spatial harmonics of the compressor were stabilized down to a characteristic slope of 0.9, yielding an 8% increase in operating flow range. Stabilization of the third spatial harmonic did not alter the stalling flow coefficient. The actuators were also used open loop to determine the forced response behavior of the compressor. A system identification procedure applied to the forced response data then yielded the compressor transfer function. The Moore-Greitzer, 2-D, stability model was modified as suggested by the measurements to include the effect of blade row time lags on the compressor dynamics. This modified Moore-Greitzer model was then used to predict both the open and closed loop dynamic response of the compressor. The model predictions agreed closely with the experimental results. In particular, the model predicted both the mass flow at stall without control and the design parameters needed by, and the range extension realized from, active control.

Boundary Layer Studies on Highly Loaded Cascades using Heated Thin Films and a Traversing Probe

1981 ◽  
Vol 103 (1) ◽  
pp. 237-246 ◽  
Author(s):  
M. L. G. Oldfield ◽  
R. Kiock ◽  
A. T. Holmes ◽  
C. G. Graham
Keyword(s):  
Boundary Layer ◽  
Transfer Rate ◽  
High Speed ◽  
Blade Profile ◽  
Aerodynamic Loading ◽  
Turbine Efficiency ◽  
Surface Transition ◽  
Turbine Vanes ◽  
Constant Temperature Anemometer ◽  
Highly Loaded

In the continuing quest for increased turbine efficiency, the part played by blade profile shape remains crucial. Three turbine vanes with successively increased aerodynamic loading were tested in the High Speed Cascade Wind Tunnel at DFVLR Braunschweig. In addition to wake traverses, measurements of the boundary layer behavior were made. These consisted of (1) use of a constant temperature anemometer to measure the fluctuating heat transfer rate on an array of thin film platinum thermometers deposited on the vanes and (2) a flattened, traversing pitot probe held against the vane surface. Transition measurement by these techniques is described.

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