An Experimental Investigation of Fatigue Performance for A Flexure Spring

In order to prevent a free-piston Stirling cryocooler failure during mission life, the flexure spring's fatigue life is most critical and important. In the current research, an effort is made to examine fatigue life. The fatigue life testing of cryocooler flexures is frequently discussed in the literature. However, more information is needed about the economic approach and hardware needed for the testing. This research paper adopts the FEA approach of flexure spring and outlines the criteria for flexure fatigue testing. A moving coil linear motor was also designed and selected for the oscillating shaft and bending special-purpose flexure spring stack to validate stiffness criteria. The 108 no. of cycles required to validate the fatigue limit were also attained using the approach in a few days when testing at a relatively high frequency

An Experimental Investigation of Fatigue Performance for A Flexure Spring

In order to prevent a free-piston Stirling cryocooler failure during mission life, the flexure spring's fatigue life is most critical and important. In the current research, an effort is made to examine fatigue life. The fatigue life testing of cryocooler flexures is frequently discussed in the literature. However, more information is needed about the economic approach and hardware needed for the testing. This research paper adopts the FEA approach of flexure spring and outlines the criteria for flexure fatigue testing. A moving coil linear motor was also designed and selected for the oscillating shaft and bending special-purpose flexure spring stack to validate stiffness criteria. The 108 no. of cycles required to validate the fatigue limit were also attained using the approach in a few days when testing at a relatively high frequency

Parametric Design and Comparative Analysis of a Special Purpose Flexure Spring

Flexure springs play pivotal role to ensure reliability and durability of the cryocooler compressors. The critical application of flexure spring intends to eliminate the wear, frictional losses and significantly vibrations. A parameter study was performed considering the design variables of a flexure spring to meet the requirements of the cryocooler compressors viz. complexity of the geometric configuration, radial and axial stiffness, fatigue life, material, etc. The parametric design approach was deployed using finite element analysis (FEA), to validate the same by experimental data to analyse the performance of the flexure spring. This paper also presents a comparative analysis of the design variables in terms of axial and radial stiffness, induced stress as well as the manufacturing methods’ considerations to optimize the design of a special purpose flexure spring for the cryocooler compressors. Furthermore, experimental study of the flexure spring was carried out in order to maximize the stroke

A Review of Recent Experimental and Theoretical Research of Dew Point Evaporative Coolers

Evaporative cooling is one of the techniques to lower the ambient air temperature according to the requirements. The technique includes the injection of moisture in the coming air, thus increasing its specific humidity. This technique can cool the air up to wet bulb temperature of the incoming air. In the recent past, the techniques are developed to lower the temperature of air without addition of moisture in the incoming air. These techniques demonstrate that the incoming air temperature can be approached near the dew point temperature of the incoming air. The present paper essentially focuses on the recent theoretical and experimental research of dew point evaporative coolers. Different flow configurations of heat exchange mediums, optimization of geometrical parameters, performance parameters (wet bulb and dew point effectiveness), energy efficiency ratio and energy saving potential are the key elements to study the prospects of dew point evaporative coolers over the conventional refrigeration systems operated by mechanical means. Dew point evaporative cooling technology is environmental friendly and has the potential in reducing the impact on earth due to global warming

A Study on Performance Enhancement of Parabolic Trough Collector

Solar energy is available in abundant quantity which can be utilized for thermal and power generation applications. The maximum solar energy extraction for application is challenging. This review focuses on the performance enhancement of parabolic trough collector. Heat transfer through absorber tube, various nanofluids with concentration is stated. Thermal efficiency increases due to the use of parabolic collector with booster reflector and glass cover over the system performance. The complex 3D analysis (ANSYS) gives accurate distribution of heat flux over the absorber tube

Comprehensive study on smart cooling techniques used for batteries

Electric vehicles are important in today’s world to reduce pollution. The demand for electric vehicles is increasing day by day. The major component is the battery for an electric vehicle which gives the power to drive motor and drives the vehicle. Continuous operation of the vehicle causes the battery to heat and while heating there are some flammable gases released which may cause a fire. The heating of batteries reduces the performance of the vehicle and reduces the efficiency, therefore there is a need for cooling techniques to keep the temperature of batteries below the critical temperature for safe operating conditions. The present study emphasizes various cooling techniques used for the battery thermal management system. Cooling improves the performance of the battery and reduces the temperature of the battery. It helps in maintaining the temperature of the battery at the desired level. Before cooling the battery, it is necessary to study the thermal behavior of the battery. Various aspects of the thermal behavior are also reported in the paper and the problems associated with the time required for charging the batteries are also discussed

Experimental analysis of magnetic field effects on compressor energy saving cooling system

A research on different refrigerants with and without influence of the magnetic field is provided in this paper. The magnetic field degree viz is four gauss. The condenser exit row was 3000, 6000, 9000 and 12000 gauss. Magnetic fields at condenser exit lines are found to reduce the consumption of the compressor energy. Through applying magnet fields on R134a, compressor energy savings was observed up to 1.35%, 6.23%, 5.40% and 4.19%, respectively, in gauss levels of 3000, 6000, 9000 and 12000, while R152a savings in energy levels were up 13.10%, 15.59% and 25.86% and R407a saving in power up to 7.3%, 9.19%, 13.05% and 12.40%. The coolant R152a saves energy in contrast to other coolant compressors. As the magnetic field strength increases, a vapor refrigeration system decreases the energy consumption of the compressor

Design and prototyping of dual axis solar tracking system for performance enhancement of solar photo-voltaic power plant

Increase in the world energy demand has made renewable energy source as one of the best option. It is finding wide utility in comparison with the other sources of energy. Solar energy is one of the major source of renewable energy. The abundance of solar energy in India makes it highly desirable to exploit but due to the limitations of technology, only a fraction of the energy can be extracted and used. This paper describes a concept for solar detection sensor implementation in Photo-Voltaic (PV) dual-axis solar tracking systems. The system uses only three units of identical light-detecting- resistors (LDR) arranged on the three sides of tetrahedron geometry and is able to track the light source position at the strongest intensity of visible light. On the basis of comparative study of outputs of all the three LDRs, the panel will tilt so as to get maximum output from the system. This system results in a wide field of view with minimum error and also has advantages in terms of sensor quantity, size of the system, accuracy and effectiveness