Experimental investigation on dependency of Terfenol-D transducers performance on working conditions

2016 ◽  
Author(s):  
M. Sheykholeslami ◽  
Y. Hojjat ◽  
S. Cinquemani ◽  
M. Tarabini ◽  
M. Ghodsi
Keyword(s):  
Experimental Investigation ◽  
Working Conditions

Experimental Investigation of a Miniature Ejector Using Water as Working Fluid

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Jingming Dong ◽  
Qiuyu Hu ◽  
Yuxin Xia ◽  
He Song ◽  
Hongbin Ma ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Temperature ◽  
Working Conditions ◽  
Thermal Energy ◽  
Nozzle Exit ◽  
Cooling System ◽  
Area Ratio ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Condensing Pressure

Abstract This paper presents an experimental investigation of a miniature ejector using water as the working fluid. The investigated ejector cooling system can utilize the thermal energy to be removed to power the cooling system and maintain the temperature of an electronic component below ambient temperature. The effects of working conditions, nozzle exit position (NXP), and area ratio on the coefficient of performance (COP) of ejector performance were investigated. Experimental results show that the miniature ejector can function well when the temperature in the high-temperature evaporator (HTE) ranges from 55 °C to 70 °C and can achieve a COP (coefficient of performance) of 0.66. With an increase of the NXP, the COP decreases, while the critical condensing pressure first increases and then decreases. As the area ratio of the miniature ejector increases, the COP increases, and the critical condensing pressure decreases.

Experimental Investigation on Marine Main Shaft Bearings With Reduced Length to Diameter Ratio

2010 ◽  
Author(s):  
Wojciech Litwin
Keyword(s):  
Experimental Investigation ◽  
Working Conditions ◽  
Hydrodynamic Pressure ◽  
Diameter Ratio ◽  
Main Shaft ◽  
Test Rig ◽  
The Past ◽  
Flexible Support ◽  
Shaft Misalignment ◽  
Significant Bearing

Water lubricated bearings are often installed on new and modernized ships. The main reasons are: unit simplicity, no danger of pollution and low price. One of the main problems connected with this the bearings of this kind is defining maximum hydrodynamic film capacity. Due to very thin hydrodynamic film and significant bearing bush deformation, the EHL model should be used for calculations. Experimental research conducted in the past was carried out on a single bearing test rig [1, 2, 3]. Unfortunately that test rig has some disadvantages. Its flexible support gives possibility of shaft misalignment for instance in case of asymmetric hydrodynamic pressure film in the bearing. The new test rig, presented in this paper gives wide research possibilities and working conditions are very similar to those on a real ship.

Experimental investigation on aerospike nozzle in different structures and working conditions

2001 ◽  
Author(s):  
Yu Liu ◽  
Guozhou Zhang ◽  
Wuye Dai ◽  
Bin Ma ◽  
Xianchen Cheng ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Working Conditions ◽  
Aerospike Nozzle

Experimental Investigation on Swirl and Heat Transfer Within a Rotor-Stator Cavity

2016 ◽  
Author(s):  
Daniele Massini ◽  
Bruno Facchini ◽  
Mirko Micio ◽  
Riccardo Da Soghe
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Mass Flow Rate ◽  
Working Conditions ◽  
Mass Flow ◽  
Flow Rate ◽  
System Effect ◽  
Flow Measurements ◽  
Wide Range ◽  
Admission System

A rotating test rig, reproducing a rotor-stator cavity with an axial admission system, has been exploited for an experimental investigation on the internal flow field and its effect on heat transfer on the stator side. Working conditions were varied in a wide range of rotating velocities and superposed mass flow rates. 2D PIV flow measurements were performed in order to obtain a radial distribution of the tangential velocity, results were used to validate numerical simulations aimed at understanding the admission system effect on the swirl distribution. Heat transfer coefficient distribution along the stator disk has been evaluated performing a steady state technique exploiting Thermo-chromic Liquid Crystals (TLC). Tests have been performed varying the superposed mass flow rate up to reaching the condition of cavity completely sealed, further increase of the mass flow rate showed to reduce the effect of the rotation. Working conditions were set in order to investigate cases missing in open literature, however few tests performed in similarity with other researches provided comparable results.

Experimental Investigation of Pressure Wave Supercharging for SI Engine

2004 ◽  
Author(s):  
Takashi Suzuki ◽  
Yasufumi Oguri ◽  
Keisuke Uchida ◽  
Masatake Yoshida
Keyword(s):  
Experimental Investigation ◽  
Working Conditions ◽  
Pressure Wave ◽  
Engine Speed ◽  
Exhaust Gas ◽  
Rotor Speed ◽  
Si Engine ◽  
Compression Efficiency ◽  
Speed Range ◽  
Engine Rotor

The objective of this paper is to find experimentally the suitable working conditions of a pressure wave supercharger (PWS) for SI engine. A belt-driven CVT was installed in order to drive the rotor of PWS to the appropriate speed regardless of engine speed. The maximum BMEP was achieved by changing speed of the PWS rotor at constant engine speed and throttle open ratio. From the experiment, the appropriate rotor speeds which led to maximum BMEP at every engine speed and throttle open ratio were achieved. The results showed that two power peaks existed during the range of the tested rotor speed. Since the drop in BMEP between these two power peaks was relatively small, the rotor speed range between these points was defined as effective rotor speed. At engine speed of 2000–4000rpm, the effective rotor speed was found at the engine-rotor ratio of 2.5. In addition, the maximum compression efficiency of PWS was 75% at engine speed of 3000rpm and the exhaust gas pressure reduced to the same level of commonly used turbochargers at all engine speed. Furthermore, results of the transient experiment showed that PWS had as good response as the small turbocharger, which was optimized for the tested engine.

Experimental Investigation of a Miniature Ejector Using Water As Working Fluid

2019 ◽  
Author(s):  
Jingming Dong ◽  
Yuxin Xia ◽  
Hongbin Ma ◽  
He Song ◽  
Zhongxi Zhao ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Temperature ◽  
Ambient Temperature ◽  
Working Conditions ◽  
Nozzle Exit ◽  
Cooling System ◽  
Area Ratio ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Condensing Pressure

Abstract This paper presents an experimental investigation of a miniature ejector using water as the working fluid. The investigated ejector cooling system can be used to keep the temperature of an electric chip below ambient temperature. The authors tested the effects of working conditions, the nozzle exit position (NXP), and the area ratio on the ejector’s performance. Experimental results show that the miniature ejector works well in the high-temperature evaporator (HTE) under temperatures ranging from 55 °C to 70 °C and can achieve a 0.66 coefficient of performance (COP). With the increase of the NXP, the COP decreased, while the critical condensing pressure first increased and then decreased. As the area ratio of the miniature ejector increased, the COP increased, and the critical condensing pressure decreased.

Experimental Investigation on Power Losses due to Oil Jet Lubrication in High Speed Gearing Systems

2017 ◽  
Author(s):  
D. Massini ◽  
T. Fondelli ◽  
B. Facchini ◽  
L. Tarchi ◽  
F. Leonardi
Keyword(s):  
Experimental Investigation ◽  
Mass Flow Rate ◽  
Working Conditions ◽  
Mass Flow ◽  
Flow Rate ◽  
High Speed ◽  
Spur Gear ◽  
Lubricating Oil ◽  
Halogen Lamp ◽  
Oil Jet

In order to reduce environmental and climate impact from air traffic, the main effort of aero-engine industry and research community is looking at a continuous increase in gearbox efficiency. With this kind of components every source of loss can be responsible for high heat loads; for this reason oil jet systems are used to provide proper cooling and lubrication of gears tooth surfaces. In the design phase it is important to predict the losses increase due to the lubricating oil jet impact on the spur gear, varying the different geometrical and working parameters such as the jet inclination, distance and the oil mass flow rate and temperature. An experimental investigation was carried out on a novel rotating test rig able to reproduce real engine working conditions in terms of speed, pressure and lubrication system, for a single spur gear. The rig consists of an electric spindle driving a shaft with a spur gear clamped on top. The gear is enclosed in a box where different air pressure conditions can be set and monitored. Pressure transducers and T-type thermocouples placed within the test box were used to measure the gear working conditions. The test box is also equipped with several optical accesses allowing flow field measurements or oil jet visualizations. The driving shaft is composed by two parts connected by a bearingless torquemeter equipped with a speedometer in order to perform torque losses and rotating velocity measurements. Tests were performed without the gear first, in order to separate the final value from the friction losses due to the driving shaft. Windage losses were characterized experimentally for every working condition and the results collected in a simple correlation that was used to separate the losses due to air windage from the ones due to the oil injection. An oil control unit allowed to impose the proper oil pressure and temperature conditions and to measure the mass flow rate. The oil jet was delivered by a spraybar placed within the gearbox, the jet to gear distance and relative angle were varied during the experiments. High speed visualizations were also performed for every test condition in order to deepen the physical understanding of the phenomena and to obtain more information on the lubrication capability of every jet condition. A high speed camera was placed in front of the gear exploiting an optical access while a halogen lamp was used to provide the proper lightening necessary due to the very low exposure time of the acquisitions. The wide experimental database provided, allowed the development of a simple numerical model able to well predict every losses contribution at the various working conditions.

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