scholarly journals Test Results from a High Power Linear Alternator Test Rig

Author(s):  
Arthur Birchenough ◽  
David Hervol ◽  
Brent Gardner
Author(s):  
Micah Hodgins ◽  
Alexander York ◽  
Stefan Seelecke

This work presents the design, fabrication and testing of a comprehensive DEAP test station. The tester is designed to perform tensile tests of planar DEAPs while measuring quantities such as tensile force, stretch, film thickness and voltage/current. The work details the specimen preparation and how the specimen is placed in the clamps. While the assembly process is performed by hand features were built-in to the design of the specimen frame and clamps to enable reliable placement and specimen geometry. Test results of the pure-shear specimen demonstrated good performance of the testing device. Although the electrode surface was rough the thickness stretch was evident during the stretching/actuation of the DEAP actuator.


2000 ◽  
Author(s):  
Rey Hsu ◽  
Stefan Fliss ◽  
Stefan Heinemann

Abstract The use of aluminum tailor welded blanks in the automotive industry continues to grow due to the fact that aluminum is lightweight and the characteristics of the tailor welded blanks. It has been found that welding of aluminum blanks with a CO2 laser is difficult but doable in a production environment. By using a high power CW Nd:YAG (Neodynium dopped Yittrium Aluminum Garnet) laser. It is possible to obtain sound results with a much wider process parameter window. However, currently, high power CO2 lasers (in the range of 8 kW) are still the dominate laser source in North America steel tailor welded blank companies. Will these lasers be able to weld aluminum tailored blanks if the demand for aluminum tailor welded blanks increases? This study employed twin spot and beam shaping methods to weld 1mm and 2 mm tailored blanks together using a high power (9 kW maximum) CO2 laser for both 5754-O and 6111-T4 alloys. The results show that high power CO2 lasers can be used to weld 5754-O and 6111-T4 aluminum alloys with very precise parameter settings. However, using beam shaping is more critical than using twin spot for 1 mm thick aluminum blanks. Once the correct parameters are applied for using beam shaping, the cup test results are better than using twin spot.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 808 ◽  
Author(s):  
Hao Tian ◽  
Wei Zhang ◽  
Lingzhi Xie ◽  
Zhichun Ni ◽  
Qingzhu Wei ◽  
...  

Thermal comfort is an important aspect to take into consideration for the indoor environment of a building integrated with a semi-transparent Photovoltaics (STPV) system. The thermal comfort of units with photovoltaic windows and that of conventional windows, which is an ordinary without PV, were evaluated via on-site tests and questionnaires. Using the thermal comfort investigation of the test rig, the maximum difference in air temperature was found to be around 5 °C between test unit and comparison unit. The predicted mean vote (PMV)–predicted percentage dissatisfied (PPD) value of the test unit was better than that of the comparison unit. It was observed that on sunny days, the PMV value ranged from 0.2 (nature) to 1.3 (slightly warm) in the test unit, and that of the comparison unit was 0.7 (slightly warm) to 2.0 (warm), thereby providing better thermal comfort, especially during mornings. The maximum difference in PPD values was found to reach 27% between the two units at noon. On cloudy days, the difference was negligible, and the thermal sensation between the foot and the head were almost the same. Fifty respondents were asked to complete a carefully designed questionnaire. The thermal sensation of the test unit was better than that of comparison unit, which corresponded with the test results. Thermal, lighting, acoustic, and other environment comfort scores were combined, and the acceptance of the test unit with the STPV windows was found to be 73.8%. The thermal sensation difference between men and women was around 5%. Thus, during summer, STPV windows can improve the thermal comfort and potentially reduce the air-conditioning load.


1984 ◽  
Vol 106 (2) ◽  
pp. 502-509 ◽  
Author(s):  
S. G. R. Hashemi ◽  
R. J. Lemak ◽  
J. A. Owczarek

A study was made of the flow in radial nozzle cascades using an air test rig and a water test rig. In the air test rig, three cobra probes were used in circumferential and spanwise traverses to determine the total pressure variations in the flow field at three radii downstream of the nozzles at which static pressure was also measured. The tests were made on two sets of nozzle blades having heights of 0.148 in. (0.376 cm) and 0.200 in. (0.508 cm), at trailing edge angles (measured from circumferential direction) of 15, 20, and 25 deg, and at two flow Mach numbers of approximately 0.2 and 0.35. The test results presented in this paper, in the form of loss coefficients and flow angles, were flow-weighted and averaged. Flow visualization in the air test rig was made on the walls bounding the nozzle blades using the graphite power-oil mixture technique. Additional tests were made on the water test rig using dye injection technique. Photographs were obtained showing clearly formation of secondary flow around each nozzle blade in the form of the leading edge vortex. The test results confirm the existence of the leading edge vortices reported peviously, and extend their study to the radial nozzle cascades.


Author(s):  
Sai S. Sreedharan ◽  
Giuseppe Vannini ◽  
Hiteshkumar Mistry

Seals used in high speed centrifugal compressors are prone to generate rotordynamic (RD) instabilities. To further understand their influence, a CFD based approach is developed. The objective of the current study is to numerically investigate and characterize the RD coefficients, representative of the dynamic seal forces. Experiments were carried out at high pressure test rig (up to 200 bar seal inlet pressure) which runs at 10000 RPM and has a high pre-swirl (about 0.9) along the same direction of rotor rotation. The rotor shaft in the experiment was instrumented with active magnetic bearings (AMBs) to linearly excite the rotor at three different frequencies: 28 Hz, 70 Hz and 126 Hz. Each frequency is characterized by amplitude of vibration and a phase. CFD simulations were carried out using commercial flow solver, using similar boundary conditions as that of experiments. The paper describes details of CFD model and its comparison against experiments. Numerical results show reasonable agreement of RD coefficients with test results. This job has to be considered as a first approach to CFD methodology applied to annular seals for the authors.


2015 ◽  
Vol 23 (04) ◽  
pp. 1550028 ◽  
Author(s):  
R. Ramkumar ◽  
M. Kesavan ◽  
A. Ragupathy

The purpose of the study is to investigate the direct evaporate cooler in hot and humid regions with two different types of agro-based materials. In our experimental study, the locally available agro materials luffa (Sponge Gourd), zizanioides (Vetiver) were used with various thickness and the experimental results were compared with mathematical values. The operating parameters of pad thickness, air velocity, were changed and the performance of the cooler was analyzed. A test rig was designed and fabricated to collect experimental data. The performance of the evaporative cooler was evaluated based on the ambient condition. The analysis of the data indicated that cooling saturation efficiency improve with decrease of air velocity and higher pad thickness. It was shown that zizanioides-based pad with 160[Formula: see text]mm thickness has the higher performance (88%) at 4.5[Formula: see text]m/s air velocity in comparison with luffa pad materials. The experimental results of outlet air temperature and number of transfer units (NTU) were compared with mathematical model. The test results were within the limit of 15% and 10% to mathematical values.


Author(s):  
Jason C. Wilkes ◽  
Tim Allison

Numerous papers have investigated the behavior of dry-friction whip and whirl; most of them consider contact between a rotor and stator at a single location. For rotors running on multiple magnetic bearings, air bearings, or bushings, equipment failure may result in rub at more than one location. For these cases, it is important to have an analytical model that characterizes possible regions of two-point contact dry-friction whip and whirl. The current work presents a general model to predict possible whirl regions for multi-contact dry-friction whip and whirl, allowing for an arbitrary phase between contact locations. In theory this method can be applied to more than two contact locations; however, a two-point contact example case is developed and compared to results from an experimental test rig developed to demonstrate multi-contact dry-friction whip and whirl in the current work.


Author(s):  
Christian Kunkel ◽  
Jan Werner ◽  
Daniel Franke ◽  
Heinz-Peter Schiffer ◽  
Fabian Wartzek ◽  
...  

Abstract With the well-known Transonic Compressor Darmstadt (TCD) in operation since 1994, profound knowledge in designing and operating a sophisticated test-rig is available at the Institute of Gas Turbines and Aerospace Propulsion of TU Darmstadt. During this period, TCD has been subject to a vast number of redesigns within different measurement campaigns (see [1], [2], [3], [4], [5], [6], [7], [8]). To expand the capabilities and ensure a sustainable process of compressor research, a new test facility was designed and built by the institute. The new test rig Transonic Compressor Darmstadt 2 (TCD2) features increased power for higher pressure ratios and higher mass-flow, a state of the art control system, increased flexibility towards different compressor geometries and modern data acquisition hardware and software. Following the successful commissioning of the test-rig in March 2018, a first measurement campaign has been conducted. Early test results regarding aerodynamic performance and aeroelastic effects of the test compressor are presented together with a detailed overview of test-rig infrastructure and control systems as well as the test compressor and the measurement hardware.


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