scholarly journals Research on space microwave energy reception technology based on electromagnetic-thermal-DC conversion

2021 ◽  
Vol 2137 (1) ◽  
pp. 012021
Author(s):  
Zhuoyue Qiu ◽  
Xinfa Wang ◽  
Zihao Qin ◽  
Xiaoshun Wang ◽  
Jinyong Fang
Keyword(s):  
Power Density ◽  
Thermal Energy ◽  
Large Deviation ◽  
Input Power ◽  
Microwave Energy ◽  
Space Environment ◽  
Total Efficiency ◽  
System Efficiency ◽  
Absorbing Materials ◽  
Absorbing Material

Abstract A new microwave energy reception method is proposed for the wireless energy transmission needs of lunar rovers combined with the lunar environment, i.e. collecting thermal energy through microwave absorbing materials, and then converting thermal energy into direct current by using temperature difference power generation devices. The article analyses the two conversion processes, microwave-thermal and thermal-DC, separately. Under the approximate condition that the temperature at both ends of the absorbing material is regarded as equal, the two conversion processes are linked by energy conservation, which theoretically leads to the temperature and total efficiency of the system at steady state. The temperature and total efficiency of the system are initially obtained by numerical simulation with respect to the thickness of the absorbing material, the receiving area and the input power density by selecting the parameters of the carbon and iron composite material at 10 GHz. The results show that there is an optimum thickness of absorbing material for a certain input power density and receiving area, which results in the highest system efficiency. The larger the receiving area and input power density in a certain range, the higher the efficiency, but beyond a certain range the system efficiency shows a decreasing trend. Also the theory and the actual will produce a large deviation when temperature is high. The article concludes that this energy receiving method has great potential for application in the space environment based on the excellent wave absorbing materials and thermoelectric components but further research is needed.

Laser Power Density Dependence in Absorption Measurements

1980 ◽  
Vol 34 (3) ◽  
pp. 311-313
Author(s):  
Peter M. Castle
Keyword(s):  
Power Density ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Continuous Wave ◽  
Strong Dependence ◽  
Wave Mode ◽  
Input Power ◽  
Absorption Cross ◽  
Continuous Wave Mode ◽  
Absorption Measurements

The absorption cross section of CF2Cl2 has been measured as a function of presure and CO2 laser input power at 10.764 μm. The laser was operated in the continuous wave mode providing a continuous energy deposition in the sample. It is shown that the absorption cross section measured has a strong dependence on input power density in the range from 5 to 15 W/cm2 and pressure in the 3 to 50 Torr regime. It is demonstrated that most of these effects can be attributed to the temperature rise in the beam interaction volume.

Characterization and Design of Honeycomb Absorbing Materials

2019 ◽  
Vol 294 ◽  
pp. 51-56
Author(s):  
Hui Min Sun ◽  
Le Chen ◽  
Zhao Zhan Gu
Keyword(s):  
Double Layer ◽  
Low Frequency ◽  
Single Layer ◽  
Electromagnetic Parameters ◽  
Honeycomb Sandwich ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
The Difference ◽  
Free Space Method ◽  
Honeycomb Sandwich Structure

Honeycomb absorbing materials are anisotropic structural materials. Depending on the size of honeycomb lattices, the absorbent content of the impregnated layer is different, the thickness of the impregnated layer is different, and the absorbing function of the impregnated honeycomb absorbing materials is also different. For the characterization of electromagnetic parameters of honeycomb absorbing materials, this paper adopts free space method for testing, uses CST software for modeling, and inverts the electromagnetic parameters of honeycomb absorbing structures. The absorbing performance of single-layer and double-layer honeycomb sandwich structures was simulated by RAM Optimizer software. The research shows that the height of the single-layer honeycomb absorbing material is 22mm. When the absorber content is 65%, 75% and 85% respectively, the harmonic peak moves slightly to the low frequency electromagnetic wave with the increase of the absorber content, but the absorbing strength decreases with the increase of the absorber content. For the double-layer honeycomb sandwich structure, the difference of absorber content in the upper and lower honeycomb absorbing materials is smaller, and the absorbing performance is stronger. When the thickness of the wave-transparent panel is thinner, the harmonic peak of the absorbing curve moves slightly to the high frequency.

scholarly journals High Power Density Electrochemical Thermocells for Inexpensively Harvesting Low-Grade Thermal Energy

2017 ◽  
Vol 29 (12) ◽  
pp. 1605652 ◽  
Author(s):  
Long Zhang ◽  
Taewoo Kim ◽  
Na Li ◽  
Tae June Kang ◽  
Jun Chen ◽  
...  
Keyword(s):  
Power Density ◽  
Thermal Energy ◽  
High Power ◽  
Low Grade ◽  
High Power Density

Low-Grade Heat Utilization Through Ultrasound-Enhanced Desorption of Activated Alumina/Water for Thermal Energy Storage

2020 ◽  
Author(s):  
Hooman Daghooghi Mobarakeh ◽  
Keshawa Bandara ◽  
Liping Wang ◽  
Robert Wang ◽  
Patrick E. Phelan ◽  
...  
Keyword(s):  
Water Vapor ◽  
Energy Storage ◽  
Thermal Energy ◽  
Input Power ◽  
Total Power ◽  
Low Grade ◽  
Ultrasonic Power ◽  
Activated Alumina ◽  
Heat Utilization ◽  
Low Grade Heat

Abstract Sorption thermal energy storage (TES) seems to be an auspicious solution to overcome the issues of intermittent energy sources and utilization of low-grade heat. Ultrasound-assisted adsorption/desorption of water vapor on activated alumina is proposed as a means of low-grade heat utilization through TES. The effects of ultrasonic power on the storing stage (desorption of water vapor) were analyzed to optimize the desorption and overall efficiencies. To determine and justify the effectiveness of incorporating ultrasound from an energy-savings point of view, an approach of constant total (heat plus ultrasound) input power of 25 W was adopted. To measure the extent of the effectiveness of using ultrasound, ultrasonic-power-to-total power ratios of 0.2 and 0.4 were investigated and the results compared with those of no-ultrasound (heat only) at the same total power. The regeneration temperature and desorption rate were measured simultaneously to investigate the effects of ultrasonication on regeneration temperature and utilization of low-grade heat. The experimental results showed that using ultrasound facilitates the regeneration of activated alumina at both power ratios without increasing the total input power. With regard to regeneration temperature, incorporating ultrasound decreases the regeneration temperature hence justifying the utilization of low-grade heat for thermal energy purposes. In terms of overall energy recovery of the adsorption thermal storage process, a new metric is proposed to justify incorporating ultrasound and any other auxiliary energy along with low-grade heat.

Study on zonal coating design of absorbing material for a stealth helicopter

2020 ◽  
Vol 92 (7) ◽  
pp. 1011-1017
Author(s):  
Shaoze Lu ◽  
Jun Huang ◽  
Mingxu Yi
Keyword(s):  
Electromagnetic Scattering ◽  
Content Type ◽  
Absorbing Materials ◽  
Weak Scattering ◽  
Secondary Scattering ◽  
Coating Methods ◽  
Absorbing Material ◽  
Reduction Effect ◽  
Coating Design ◽  
Coating Weight

Purpose By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS. Design/methodology/approach To alleviate the weight-increasing problem caused by a large number of coating of absorbing materials, a method for zonal coating of absorbing materials for a stealth helicopter was proposed. By appropriately reducing the thickness of the coating at the secondary scattering locations, the amount of coating used is significantly reduced. Findings Compared with the full-coated, the zonal coating scheme achieves the corresponding RCS reduction effect. Practical implications Zonal coating design can achieve the effect of reducing coating weight and cost. Originality/value The effects of different coating methods on RCS were verified by electromagnetic scattering simulation, and the applicability of the zonal coating design of the absorbing material to the stealth helicopter was verified.

Radar Absorbing Materials Based on Metamaterials

2010 ◽  
Vol 75 ◽  
pp. 215-223
Author(s):  
Andrey Nikolayevich Lagarkov ◽  
Vladimir Nikolayevich Kisel ◽  
Vladimir Nikolayevich Semenenko
Keyword(s):  
Electromagnetic Wave ◽  
Reflection Coefficient ◽  
Frequency Band ◽  
Radar Absorbing Material ◽  
Wide Range ◽  
Absorbing Materials ◽  
Different Types ◽  
Absorbing Material ◽  
Wave Incidence

The use of metamaterial for design of radar absorbing material (RAM) is discussed. The typical features of the frequency dependencies of , , ,  of composites manufactured of different types of resonant inclusions are given as an example. The RAM characteristics obtained by the use of the composites are given. It is shown that it is possible to use for RAM design the metamaterials with both the positive values of ,  and negative ones. Making use of the frequency band with negative  and  it is possible to create a RAM with low reflection coefficient in a wide range of the angles of electromagnetic wave incidence.

Modeling the Thermomechanical Response of Ore Materials During Microwave Processing

1994 ◽  
Vol 347 ◽  
Author(s):  
R. L. Williamson ◽  
J. B. Salsman ◽  
W. K. Tolley
Keyword(s):  
Power Density ◽  
Host Rock ◽  
Mechanical Response ◽  
Numerical Study ◽  
Particle Diameter ◽  
Microwave Energy ◽  
Uniaxial Tensile ◽  
Mineral Particle ◽  
Rock Materials ◽  
Uniaxial Tensile Strength

ABSTRACTA finite element numerical model is used to predict the thermal and mechanical response of mineral-bearing ores irradiated by microwave energy. The model considers a small, spherical, pyrite particle surrounded by a matrix of calcite. Power density data are determined from the dielectric properties of the mineral and host rock materials at typical microwave frequencies and power capabilities. The effects of varying power density and mineral particle diameter are studied. Using power densities within the expected achievable range for pyrite, significant temperature differences are predicted between the mineral particle and host rock. These temperature gradients lead to circumferential tensile stresses in the host rock well in excess of the reported uniaxial tensile strength of common rock materials. It is shown that, for a fixed microwave energy source, both the temperature difference between the mineral and host rock, and the peak tensile stress in the host rock are reduced as the mineral particle size is reduced. Recent experimental efforts to corroborate this numerical study are briefly described.

scholarly journals THICKNESS INFLUENCE ON ABSORBING PROPERTIES OF STRATIFIED COMPOSITE MATERIALS

2015 ◽  
Vol 21 (4) ◽  
pp. 28-34
Author(s):  
IULIANA IAȘNICU (STAMATE) ◽  
OVIDIU VASILE ◽  
RADU IATAN
Keyword(s):  
Composite Material ◽  
Sound Pressure ◽  
Layered Composite ◽  
Sound Level ◽  
Pressure Level ◽  
Sound Level Meter ◽  
Absorbing Materials ◽  
Absorbing Material ◽  
Study Case ◽  
Level Meter

Plates known as sound absorbing materials: textiles recovered fabrics plus polyethylene are made layered composite material intended to be used to encapsulate industrial engines, as sources of noise in the production departments. Influence of thickness sound-absorbing material can be supported by the values obtained for the absorption coefficient, but it can be studied as a study case in the anechoic chamber, where the sound pressure level is measured with a sound level meter. Cases captured: a free engine; the engine placed in a metallic cube and motor inserted; metal cube that was doubled separately with one material and then with the composite material proposed. For each situation are eight determinations on the perimeter of a circle with a radius of one meter from the source of the noise. Plot a graph of experimental results that support the idea: greater thickness of the layer of material will cause a better absorption of noise.

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