Influence of Fuel/Oxygen Ratio on Coating Properties and Cavitation Resistance of WC and Cr3C2 Cermet Coatings Deposited by HVOF

2021 ◽  
Author(s):  
A. Becker ◽  
K. Bertoul ◽  
A.G.M. Pukasiewicz ◽  
I.B.A.F. Siqueira ◽  
A. Chicoski ◽  
...  
Keyword(s):  
Cavitation Resistance ◽  
Test Results ◽  
Coating Properties ◽  
Critical Part ◽  
Cermet Coatings ◽  
Turbine Performance ◽  
Particle Velocities ◽  
Thermal Spray Processes ◽  
Oxygen Ratio ◽  
Coating Hardness

Abstract Hydroelectric turbines are strongly affected by cavitation and the damage it can cause to critical part surfaces and profiles. The study of thermal spray processes and materials is thus relevant to improving turbine performance. The main objective of this work is to evaluate the influence of fuel-oxygen ratio on tungsten- and chromium-carbide cermet coatings deposited by HVOF. Particle velocity and temperature were measured as were coating hardness, porosity, and cavitation resistance. Higher particle velocities were obtained at higher fuel ratios, producing harder, denser coatings with better cavitation resistance. Based on test results, the wear mechanism starts with the nucleation of the cavitation that occurs in the pores, resulting in the formation of craters and the eventual detachment of lamellae as indicated by the smoothness of the surface.

Experimental Results of Full Scale Air-Cooled Turbine Tests

1976 ◽  
Vol 98 (1) ◽  
pp. 103-113
Author(s):  
H. Nouse ◽  
A. Yamamoto ◽  
T. Yoshida ◽  
H. Nishimura ◽  
K. Takahara ◽  
...  
Keyword(s):  
Axial Flow ◽  
Aircraft Engine ◽  
Aerodynamic Characteristics ◽  
Experimental Results ◽  
Test Results ◽  
Test Apparatus ◽  
Two Stage ◽  
Turbine Cooling ◽  
Turbine Performance ◽  
Air Turbine

In order to investigate several problems associated with the turbine cooling, an air-cooled two-stage axial flow turbine for an aircraft engine application was designed. Aerodynamic characteristics of the two-stage turbine without coolants were obtained first from the cold air turbine tests, and predictions of the turbine performance with supplying of coolants were made using the test results. Following these experiments, cooling tests of the first stage turbine were conducted in the range of turbine inlet gas temperatures lower than 1360 K by the another test apparatus. The descriptions of the turbine and the two test apparatus and the experimental results of the two test turbines are presented. The performance prediction, coolant effects and Reynolds number effect on the turbine performance are also described.

Experimental and Analytical Study of Sub-Watt Scale Tesla Turbine Performance

2012 ◽  
Author(s):  
Vince D. Romanin ◽  
Vedavalli G. Krishnan ◽  
Van P. Carey ◽  
Michel M. Maharbiz
Keyword(s):  
Analytical Study ◽  
High Efficiency ◽  
Analytical Models ◽  
Working Fluid ◽  
Test Results ◽  
Turbine Performance ◽  
Model Match ◽  
Performance Trends ◽  
Computational Fluid Dynamics Cfd ◽  
Scaling Down

Viscous turbines, like the Tesla turbine, can be manufactured inexpensively at small scales, are robust, and are low maintenance, making them ideal for micro to watt scale energy harvesting applications. However, high efficiency turbines have not yet been demonstrated at small (sub-watt) scales. Previous studies have developed analytical models of turbine performance and analyzed parametric trends in performance for larger turbines and for air as a working fluid. In this study, the same parametric trends in performance are compared to test data for a micro-scale Tesla turbine with water as a working fluid. A Computational Fluid Dynamics (CFD) model is then compared to both the analytical and experimental turbine efficiencies. Tesla turbines were tested with 8 different nozzle configurations, 3 different rotor configurations, and several different flow rates. The test results show that several of the performance trends predicted by the analytical model match experimental results. The CFD solutions of the flow field are then used to help reconcile areas where the analytical predictions do not match experimental data. Certain trends in turbine performance are discussed, and the feasibility of further scaling down Tesla turbines (< 1 cm) is discussed.

The Application of Ultra High Lift Blading in the BR715 LP Turbine

2001 ◽  
Vol 124 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Frank Haselbach ◽  
Heinz-Peter Schiffer ◽  
Manfred Horsman ◽  
Stefan Dressen ◽  
Neil Harvey ◽  
...  
Keyword(s):  
Test Results ◽  
Percent Reduction ◽  
Original Design ◽  
High Lift ◽  
Design Intent ◽  
Pressure Distributions ◽  
Turbine Performance ◽  
Unsteady Wake ◽  
Boundary Layer Interaction ◽  
Lp Turbine

The original LP turbine of the BR715 engine featured “High Lift” blading, which achieved a 20-percent reduction in aerofoil numbers compared to blading with conventional levels of lift, reported in Cobley et al. (1997). This paper describes the design and test of a re-bladed LP turbine with new “Ultra High Lift” aerofoils, achieving a further reduction of approximately 11 percent in aerofoil count and significant reductions in turbine weight. The design is based on the successful cascade experiments of Howell et al. (2000) and Brunner et al. (2000). Unsteady wake-boundary layer interaction on these low-Reynolds-number aerofoils is of particular importance in their successful application. Test results show the LP turbine performance to be in line with expectation. Measured aerofoil pressure distributions are presented and compared with the design intent. Changes in the turbine characteristics relative to the original design are interpreted by making reference to the detailed differences in the two aerofoil design styles.

scholarly journals Experimental Investigation of Supersonic Turbine Performance

1989 ◽  
Author(s):  
John W. Kurzrock
Keyword(s):  
Experimental Investigation ◽  
Rotor Blade ◽  
Single Stage ◽  
Channel Width ◽  
Test Results ◽  
Turbine Performance ◽  
Comparable Performance

This paper presents the performance obtained from testing single-stage, full-admission, axial supersonic turbine configurations. A matrix of four nozzle and two rotor blade configurations was evaluated. Turbine pressure ratios were varied from 33 to 140 for velocity ratios of 0.2 to 0.5. The test results indicate that constant-channel width and variable-channel width rotor blading give comparable performance. Optimal nozzle and blade configurations yielded turbine efficiencies of 77 percent.

The Application of Ultra High Lift Blading in the BR715 LP Turbine

2001 ◽  
Author(s):  
Frank Haselbach ◽  
Heinz-Peter Schiffer ◽  
Mannfred Horsman ◽  
Stefan Dressen ◽  
Neil Harvey ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Test Results ◽  
Original Design ◽  
High Lift ◽  
Design Intent ◽  
Pressure Distributions ◽  
Turbine Performance ◽  
Unsteady Wake ◽  
Boundary Layer Interaction ◽  
Lp Turbine

The original LP turbine of the BR715 engine featured “High Lift” blading, which achieved a 20% reduction in aerofoil numbers compared to blading with conventional levels of lift - reported in Cobley et al. (1997). This paper describes the design and test of a re-bladed LP turbine with new “Ultra High Lift” aerofoils, achieving a further reduction of approximately 11% in aerofoil count and significant reductions in turbine weight. The design is based on the successful cascade experiments of Howell et al. (2000) and Brunner et al. (2000). Unsteady wake - boundary layer interaction on these low Reynolds number aerofoils is of particular importance in their successful application. Test results show the LP turbine performance to be in line with expectation. Measured aerofoil pressure distributions are presented and compared with the design intent. Changes in the turbine characteristics relative to the original design are interpreted by making reference to the detailed differences in the two aerofoil design styles.

Testing State-Space Controls for the Controls Advanced Research Turbine

2006 ◽  
Vol 128 (4) ◽  
pp. 506-515 ◽  
Author(s):  
Alan D. Wright ◽  
Lee J. Fingersh ◽  
Mark J. Balas
Keyword(s):  
State Space ◽  
Control Systems ◽  
Dynamic Loads ◽  
Test Results ◽  
Future Studies ◽  
Energy Capture ◽  
Torsion Mode ◽  
Turbine Performance ◽  
Advanced Controls ◽  
Turbine Speed

Control can improve wind turbine performance by enhancing energy capture and reducing dynamic loads. At the National Renewable Energy Laboratory, we are implementing and testing state-space controls on the controls advanced research turbine (CART), a turbine specifically configured to test advanced controls. We show the design of control systems to regulate turbine speed in region 3 using rotor collective pitch and reduce dynamic loads in regions 2 and 3 using generator torque. These controls enhance damping in the first drive train torsion mode. We base these designs on sensors typically used in commercial turbines. We evaluate the performance of these controls by showing field test results. We also compare results from these modern controllers to results from a baseline controller for the CART. Finally, we report conclusions to this work and outline future studies.

scholarly journals Integration of the Brayton and Rankine Cycle to Maximize Gas Turbine Performance: A Cogeneration Option

1984 ◽  
Author(s):  
R. L. Messerlie ◽  
J. R. Strother
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Cycle Performance ◽  
Test Results ◽  
Steam Generation ◽  
Turbine Performance ◽  
Exhaust Heat ◽  
International Power ◽  
Good Agreement

The Brayton and Rankine cycles are well known and widely used in their own way to generate power. A combining of the fluids of the two cycles has been proposed by International Power Technology and tested by Allison Gas Turbine Operations. Steam generated by the exhaust heat is mixed with the fuel and air in the gas turbine combustion chamber prior to expansion through the turbine. The thermal efficiency of an existing engine can be increased by 40% and power output by 60% at constant turbine temperature. This concept is identified as the Dual Fluid Cycle (DFC). In addition to the basic improvement in cycle performance, the DFC provides an added degree of flexibility to the power plant engineer in his effort to satisfy plant needs for power, heat, and steam. Allison test results of this concept on a Model 501-KB engine have been correlated with a computer model of the engine and show good agreement. This paper will show how the DFC can be used to maximize thermal efficiency while meeting the requirement for power and steam in selected cases. Comparisons will be made to other options for power and steam generation.

scholarly journals The Use of Mathematical Modeling in the Analysis of Gas Turbine Compressor Unit Test Data

1981 ◽  
Author(s):  
L. J. Williams
Keyword(s):  
Mathematical Modeling ◽  
Gas Turbine ◽  
Test Data ◽  
Performance Test ◽  
Test Results ◽  
Compressor Unit ◽  
Turbine Performance ◽  
Modelling Procedure ◽  
Gas Turbine Compressor ◽  
Actual Test

A clear need exists for methods of establishing the validity of gas turbine performance test results and diagnosing the causes of performance problems. Published methods depend on the results of simulating faults in complex mathematical models of the engines and are only capable of diagnosing combinations of faults previously simulated. A very simple mathematical modelling procedure is described which allows the analyst to test his own hypothesis of engine faults and so identify instrumentation errors and discover conditions not previously considered. Application of modelling to actual test data is demonstrated.

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