CFD Modeling and Performance Analysis of a Thermoacoustically Driven Thermoacoustic Refrigerator

Although thermoacoustic devices comprise simple components, the design of these machines is very challenging. In order to predict the behavior and optimize the performance of a thermoacoustic refrigerator driven by a standing-wave thermoacoustic engine, considering the changes in geometrical parameters, two analogies have been presented in this paper. The first analogy is based on CFD analysis where a 2D model is implemented to investigate the influence of stack parameters on the refrigerator performance, to analyze the time variation of the temperature gradient across the stack, and to examine the refrigerator performance in terms of refrigeration temperature. The second analogy is based on the use of an optimization algorithm based on the simplified linear thermoacoustic theory applied for designing thermoacoustic refrigerators with different stack parameters and operating conditions. Simulation results show that the engine produced a high-powered acoustic wave with a pressure amplitude of 23[Formula: see text]kPa and a frequency of 584[Formula: see text]Hz and this wave applies a temperature difference across the refrigeration stack with a cooling temperature of 292.8[Formula: see text]K when the stacks are positioned next to the pressure antinode. The results from the algorithm give the ability to design any thermoacoustic refrigerator with high performance by picking the appropriate parameters.

THERMOACOUSTIC ENGINE AS A LOW-POWER COGENERATION ENERGY SOURCE FOR AUTONOMOUS CONSUMER POWER SUPPLY

The article deals with the issue of using a thermoacoustic engine as a low-power cogeneration source of energy for autonomous consumer power supply capable of operating on various types of fuel and wastes subject to combustion. The analysis of the world achievements in this field of energy has been carried out. A number of advantages make it very promising for developing energy sources capable of complex production of electrical and thermal energy with a greater efficiency than that of present day thermal power plants. The proposed scheme of a thermal power plant is based on the principle of a Stirling engine, but it uses the most efficient and promising thermoacoustic converter of heat into mechanical vibrations, which are then converted into electric current. The article contains a mathematical apparatus that explains the basic principles of the developed thermoacoustic engine. To determine the main parameters of the thermoacoustic engine, the methods of computer modeling in the DeltaEC environment have been used. A layout diagram of the laboratory sample of a thermal power plant has been proposed and the description of its design has been given. It has been proposed to use dry saturated steam as the working fluid, which makes it possible to increase the generated power of the thermoacoustic engine.

Turbin Hibrid Bi-Directional Sebagai Pemanen Energi pada Thermoacoustic Engine

Bi-directional turbines that are commonly applied to convert wave energy into motion energy are the types of Impulse turbines and Wells turbines. Both types of turbines each have advantages and disadvantages. In this research, hybrid turbine type is designed and made to bridge the weaknesses in impulse turbine and turbine wells. Hybrid turbines are made by placing impulse turbines on the outside while turbine wells placed on the inside. In this research, the variation of hybrid bi-directional turbine design aims to find out the most optimal design of this turbine type. Six variations were carried out including a hub to tip ratio of 0.5 with 4 and 5 Wells blades, a hub to tip ratio of 0.6 with 4 and 5 Wells blades, and a hub to tip ratio of 0.7 with 4 and 5 Wells blades. From the test results on thermoacoustic engine media, based on the hub to tip ratio, the most optimal hub to tip ratio is in the order of 0.7 then 0.6, and 0.5. Whereas based on the number of Wells blade, obtained the number of Wells blade 5 is more optimal than the number of Wells blade 4.