Modeling and experimental evaluation of torque loss in turbine test rig for accurate turbine performance evaluation

2012 ◽  
Vol 26 (2) ◽  
pp. 473-479 ◽  
Author(s):  
Jeong-Seek Kang ◽  
Soo-Seok Yang
Keyword(s):  
Performance Evaluation ◽  
Experimental Evaluation ◽  
Test Rig ◽  
Turbine Performance ◽  
Torque Loss

Modeling and Experimental Evaluation on Torque Loss in Turbine Test Rig

2008 ◽  
Author(s):  
Jeong-Seek Kang ◽  
Bong-Jun Cha ◽  
Iee-Ki Ahn
Keyword(s):  
High Precision ◽  
Experimental Evaluation ◽  
Dissipated Energy ◽  
Test Rig ◽  
Mechanical Loss ◽  
Axial Turbine ◽  
Accurate Evaluation ◽  
Turbine Performance ◽  
Torque Loss ◽  
Bearing Loss

To evaluate the performance of a turbine through turbine rig test, torque or power generated from the test turbine should be measured. This is measured from a dynamometer or torquesensor installed in the test rig. So, to evaluate the performance of turbine with high precision, the accurate measurement of power or torque is necessary. However, there is an intrinsic difficulty as not all the power generated by the turbine is measured by the dynamometer or torquesensor. A small portion of power generated from test turbine is dissipated through bearing loss and windage loss. This dissipated energy is called mechanical loss of test rig. Therefore, it is necessary to measure the mechanical loss of the test rig for the accurate evaluation of the turbine performance. This paper divides mechanical loss as bearing loss, disk windage loss and extra windage loss. Spin down tests are performed in a 1-stage axial turbine test rig to evaluate each losses. It is found that the dominant loss is bearing loss and the total mechanical loss amounts to 0.78∼1.4% of energy generated at the turbine. And the effect of bearing temperature is investigated and it is found that the mechanical loss is dependent on the bearing temperature and that it increases with decreasing bearing temperature.

Axial Turbine Performance Evaluation. Part B—Optimization With and Without Constraints

1968 ◽  
Vol 90 (4) ◽  
pp. 349-359 ◽  
Author(s):  
O. E. Balje´ ◽  
R. L. Binsley
Keyword(s):  
Reynolds Number ◽  
Performance Evaluation ◽  
Reference Value ◽  
Tip Clearance ◽  
Strong Function ◽  
Turbine Performance ◽  
Wide Range ◽  
Leakage Area ◽  
Partial Admission ◽  
Specific Speed

The maximum obtainable efficiency and associated geometry have been calculated based on the use of generalized loss correlations from Part A and are presented for full and partial admission turbines over a wide range of specific speeds. The calculated effects of varying values of Reynolds number, tip clearance, and trailing edge thickness on turbine performance are presented. Because of the anticipated difficulty in fabricating some of the optimum geometries calculated, the effects of using nonoptimum values of geometric parameters on attainable efficiency have also been investigated. The derating factor for machine Reynolds number is shown to be a strong function of specific speed, varying from 0.96 at a specific speed of 100, to 0.6 at a specific speed of 3, when Reynolds number is 105 compared to a reference value of 106. The derating factor for tip clearance is shown to be similar to what would be expected if the clearance area were considered as a leakage area. The use of blade heights, blade numbers, rotor exit angles, and degrees of reaction varying from the optimum by 25 percent produce maximum derating factors of 0.99, 0.98, 0.985, and 0.97, respectively, when compared to full optimum values.

scholarly journals Design and Experimental Evaluation of a Single-Actuator Continuous Hopping Robot Using the Geared Symmetric Multi-Bar Mechanism

2018 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Long Bai ◽  
Fan Zheng ◽  
Xiaohong Chen ◽  
Yuanxi Sun ◽  
Junzhan Hou
Keyword(s):  
Performance Evaluation ◽  
Energy Storage ◽  
Experimental Evaluation ◽  
State Of The Art ◽  
Energy Conversion Efficiency ◽  
Servo Motor ◽  
Hopping Robot ◽  
Closed Chain ◽  
Hopping Robots ◽  
And Performance

This paper proposes the design and performance evaluation of a miniaturized continuous hopping robot RHop for unstructured terrain. The hopping mechanism of RHop is realized by an optimized geared symmetric closed-chain multi-bar mechanism that is transformed from the eight-bar mechanism, and the actuator of RHop is realized by a servo motor and the clockwork spring, thereby enabling RHop to realize continuous hopping while its motor rotates continuously only in one direction. Comparative simulations and experiments are conducted for RHop. The results show that RHop can realize better continuous hopping performance, as well as the improvement of energy conversion efficiency from 70.98% to 76.29% when the clockwork spring is applied in the actuator. In addition, comparisons with some state-of-the-art hopping robots are conducted, and the normalized results show that RHop has a better energy storage speed.

Study on Wear Mechanism of an AlSi–Hexagonal Boron Nitride Abradable Seal Coating

2015 ◽  
Vol 1095 ◽  
pp. 655-661 ◽  
Author(s):  
Tong Liu ◽  
Yue Guang Yu ◽  
Jie Shen ◽  
Jian Ming Liu ◽  
Qiu Yuan Lu
Keyword(s):  
High Temperature ◽  
Wear Mechanism ◽  
Hexagonal Boron Nitride ◽  
Xrd Analysis ◽  
Test Rig ◽  
Speed Test ◽  
Turbine Performance ◽  
Temperature Combustion ◽  
Combustion Region ◽  
High Temperature Combustion

To improve gas turbine performance, it is essential to decrease back flow gases in the high-temperature combustion region of turbo machine by reducing the shroud/rotor gap. An abradable seal coating will function effectively. Therefore, it is significant to identify and characterize the main wear mechanisms occurring on turbo machinery seals. A high temperature and speed test rig has been developed by BGRIMM for testing the AlSi–hBN abradable seal coating and Ti-6Al-4V dummy blade. Impact velocities between 150 and 300m·s-1 and incursion rates between 5.0 and 480 μm·s-1 have been applied. It was found that incursion rate has a greater impact on the wear mechanism of the AlSi–hBN coating, with tests at low incursion rate showing a obvious grooving and little micro-rupture, whereas tests at high incursion rate showing significant cutting and adhesion. The present work also shown that tests at low incursion rate related to a higher IDR, which means that blade suffered a serious wear. The investigation together with SEM and XRD analysis on the coating revealed both wear and adhesion occurred at the end of the test.

Effects of Inlet Air Distortion on Gas Turbine Combustion Chamber Exit Temperature Profiles

2015 ◽  
Author(s):  
O. Maqsood ◽  
M. LaViolette ◽  
R. Woodason
Keyword(s):  
Combustion Chamber ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Temperature Profiles ◽  
Toroidal Vortex ◽  
Uniform Temperature ◽  
Sauter Mean Diameter ◽  
Test Rig ◽  
Turbine Performance ◽  
Exit Temperature

Localized damage to turbine inlet nozzles is typically caused by non-uniform temperature distributions at the combustion chamber exit. This damage results in decreased turbine performance and can lead to expensive repair or replacement. A test rig was designed and constructed for the Rolls-Royce Allison 250-C20B dual-entry combustion chamber to investigate the effects of inlet air distortion on the combustion chamber’s exit temperature fields. The rig includes a purposely built water cooled thermocouple rake to sweep the exit plane of the combustion chamber. Test rig operating conditions simulated normal engine cruise conditions by matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either combustion chamber inlet. An even distribution of inlet air to the combustion chamber did not produce a uniform temperature profile and varying the inlet distribution of air exacerbated the profile’s non-uniformity. The design of the combustion chamber promoted the formation of an oval-shaped toroidal vortex inside the combustion liner, causing localized hot and cool sections separated by 90° that were apparent in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most airflow and decreasing the temperature of the hot section on the opposite side.

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