Study of thermoacoustic refrigeration with variations of resonator length and stack space

2009 ◽  
Author(s):  
D. P. Sari ◽  
W. Hendradjit ◽  
I. B. A. Putra
Keyword(s):  
Resonator Length ◽  
Thermoacoustic Refrigeration

scholarly journals Performance analysis of the thermoacoustic refrigerator with the standing wave and air as a working fluid

2018 ◽  
Vol 44 ◽  
pp. 00063 ◽  
Author(s):  
Jakub Kajurek ◽  
Artur Rusowicz
Keyword(s):  
Temperature Difference ◽  
High Reliability ◽  
Power Input ◽  
Acoustic Power ◽  
Operating Frequency ◽  
Working Fluid ◽  
Resonator Length ◽  
Environmental Friendliness ◽  
The Impact ◽  
Thermoacoustic Refrigerator

Thermoacoustic refrigerator is a new and emerging technology capable of transporting heat from a low-temperature source to a high-temperature source by utilizing the acoustic power input. These devices, operating without hazardous refrigerants and owning no moving components, show advantages of high reliability and environmental friendliness. However, simple to fabricate, the designing of thermoacoustic refrigerators is very challenging. This paper illustrates the impact of significant factors on the performance of the thermoacoustic refrigerator which was measured in terms of the temperature difference generated across the stack ends. The experimental device driven by a commercial loudspeaker and air at atmospheric pressure as a working fluid was examined under various resonator length and operating frequencies. The results indicate that appropriate resonator’s length and operating frequency lead to an increase in the temperature difference created across the stack. The maximum values were achieved for operating frequency equalled to 200 and 300 Hz whereas resonator length corresponded to the half-length of the acoustic wave for these frequencies. The results of experiment also confirm that relationship between these parameters is strongly affected by the stack spacing, which in this research was equalled to 0.4 mm.

scholarly journals Увеличение эффективности тандема полупроводниковый лазер-оптический усилитель на основе самоорганизующихся 8s квантовых точек

2021 ◽  
Vol 55 (12) ◽  
pp. 1223
Author(s):  
А.Е. Жуков ◽  
Н.В. Крыжановская ◽  
Э.И. Моисеев ◽  
А.С. Драгунова ◽  
А.М. Надточий ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Excited State ◽  
Laser Diode ◽  
Ground State ◽  
Semiconductor Optical Amplifier ◽  
Optical Transition ◽  
Optical Amplifier ◽  
Rate Equations ◽  
Resonator Length ◽  
Optimal Value

The rate equations are used to analyze the characteristics of a tandem consisting of a laser diode and a semiconductor optical amplifier made of a single heterostructure with quantum dots. The optimal value of the current distribution coefficient the amplifier and the laser, as well as the optimal resonator length that provides the highest output power of the tandem were determined. It is shown that the use of the tandem allows, at the same total consumed current, to significantly (more than 4 times for 1 A) increase the power emitted through the ground-state optical transition in comparison with that achievable with a laser diode solely being limited by the onset of lasing through an excited-state optical transition.

Comparison of a Thermoacoustic Refrigerator Stack Performance: Mylar Spiral, Celcor Substrates and 3D Printed Stacks

2019 ◽  
Vol 27 (03) ◽  
pp. 1950021
Author(s):  
N. A. Zolpakar ◽  
N. Mohd-Ghazali
Keyword(s):  
Optimal Design ◽  
Temperature Difference ◽  
Cooling System ◽  
Coefficient Of Performance ◽  
Design Parameters ◽  
Optimized Design ◽  
Multi Objective Genetic Algorithm ◽  
Potential Alternative ◽  
3D Printed ◽  
Thermoacoustic Refrigeration

Although the thermoacoustic refrigeration (TAR) system has been recognized as a potential alternative environmentally cooling system, the low coefficient of performance (COP) has yet to make it marketable. One major factor contributing towards the low COP is the fabrication method applied to the stack component which is the most important component in the TAR. In this paper, comparison of the performance of a (i) 3D printed stack, (ii) a hand fabricated Mylar stack and (iii) an off-the-shelf Celcor substrates stack has been done; these being based on optimized design parameters using Multi-Objective Genetic Algorithm (MOGA). The performance is determined from the temperature attained at the cold end of the stack and the temperature difference across the stack. Experimental results showed that the 3D printed stack has the best performance by achieving a temperature, [Formula: see text]C at the cold end and a temperature difference of [Formula: see text]C across the stack, about 60% of the designed temperature difference even though the fabricated 3D printed stack deviated from the optimal design due to fabrication constraint as compared to that of the Mylar stack which was closer to the optimal design. This 3D printing of the stack promises a big potential in the improvement of the TAR performance because of the consistency achievable with the precise dimensions of the stack.

Mechanics of the influx phase in the jet regurgitant mode of a powered resonance tube

2019 ◽  
Vol 18 (2-3) ◽  
pp. 279-298 ◽  
Author(s):  
Bhavraj Thethy ◽  
David Tairych ◽  
Daniel Edgington-Mitchell
Keyword(s):  
Shock Wave ◽  
High Speed ◽  
Fluid Velocity ◽  
Velocity Variation ◽  
Shock Strength ◽  
Velocity Change ◽  
Resonator Length ◽  
Time Resolved ◽  
Reflected Waves ◽  
Shock Position

Time-resolved visualisation of shock wave motion within a powered resonant tube (PRT) is presented for the regurgitant mode of operation. Shock position and velocity are measured as functions of both time and space from ultra-high-speed schlieren visualisations. The shock wave velocity is seen to vary across the resonator length for both the incident and reflected waves. Three mechanisms are explored as explanations for the variation in velocity: change in local fluid velocity, variation in shock strength and variations in local temperature. For the incident wave, local fluid velocity and shock strength are extracted from the data and both are demonstrated to contribute to the observed variation, with a non-trivial remainder likely explained by variation in temperature.

Influence of Resonator Length on Performance of Nitride TJ VCSEL

2019 ◽  
Vol 55 (6) ◽  
pp. 1-9 ◽  
Author(s):  
Robert P. Sarzala ◽  
Patrycja Spiewak ◽  
Michal Wasiak
Keyword(s):  
Resonator Length

Studies on the Acoustic Characteristics of the Hartmann Acoustic Generator

2014 ◽  
Vol 472 ◽  
pp. 364-368
Author(s):  
Ren Song Chen ◽  
Xiu Hai Chen ◽  
Xin Jun Gao ◽  
Jun Bo Jia ◽  
Sheng Ping He ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Acoustic Model ◽  
Resonator Length ◽  
Acoustic Characteristics

Based on the method FW-H acoustic model, how the parameters influence acoustic characteristics of the Hartmann acoustic generator were studied, which are resonator length, spacing between the jet and resonator tube, the diameter of resonator tube. The conclusions were induced just as below. The total sound pressure level (SPL) increases with the length of resonator tube, while the magnitude of fundamental frequency is reverse. And the total SPL oscillates with the increase of spacing between jet and resonator, and the oscillating distance period increases with diameter of resonator tube. And the Hartmann generator with larger diameter of resonator tube can produce a higher SPL. The results of the paper provide the instructing meaning for the application of the Hartmann acoustic generator.

Blow-out phenomena of cooled and heated air from a thermoacoustic refrigeration tube

2000 ◽  
Vol 2000.4 (0) ◽  
pp. 121-124
Author(s):  
Toshitsugu HARA ◽  
Noritoshi OGAWA ◽  
Kazuyoshi SHIMIZU
Keyword(s):  
Heated Air ◽  
Thermoacoustic Refrigeration
Sign in / Sign up

Export Citation Format

Share Document