Thermal Science最新文献_第2页

Linear frequency modulation infrared thermal imaging detection technology for GFRP/PMI foam sandwich structure defects 线性调频红外热成像检测GFRP/PMI泡沫夹层结构缺陷技术

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci220806007s

Yanping Song, Q. Tang, Chi-wu Bu, Yumei Lu, Peng Xu

{"title":"Linear frequency modulation infrared thermal imaging detection technology for GFRP/PMI foam sandwich structure defects","authors":"Yanping Song, Q. Tang, Chi-wu Bu, Yumei Lu, Peng Xu","doi":"10.2298/tsci220806007s","DOIUrl":"https://doi.org/10.2298/tsci220806007s","url":null,"abstract":"As one of the important structures of composite materials, PMI foam sandwich structure is prone to debonding and delamination defects during manufacturing and service, which seriously affects the mechanical properties of materials. Therefore, it is necessary to detect the defects of foam sandwich structure. A linear frequency modulation (LFM) infrared thermal wave nondestructive testing system was built to study the correlation between the geometric characteristics (diameter and depth) of the defect and the surface temperature signal and its influence on the detection effect. The image sequence is processed by principal component analysis, discrete Fourier transform, thermal wave signal reconstruction and other algorithms. Studies have shown that: the larger the defect diameter, the shallower the depth, easy to detect defects, detection effect is good. The detection system can effectively detect and identify debonding and delamination defects. The thermal wave signal reconstruction method is superior to the principal component analysis method and the discrete Fourier transform method in the signal-to-noise ratio (SNR)index, which improves the quality of the image and is conducive to the effective identification of the image surface defect information.","PeriodicalId":23125,"journal":{"name":"Thermal Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68246422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CFD analysis of the effect of internal peak angle and mass flow rates on the thermal performance of solar air heater with triangle cross-section 内峰角和质量流量对三角截面太阳能空气加热器热性能影响的CFD分析

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci220918046a

Walid Amara, Yashar Aryanfar, H. Koten, A. Bouabidi, M. Chrigui, J. Alcaraz

{"title":"CFD analysis of the effect of internal peak angle and mass flow rates on the thermal performance of solar air heater with triangle cross-section","authors":"Walid Amara, Yashar Aryanfar, H. Koten, A. Bouabidi, M. Chrigui, J. Alcaraz","doi":"10.2298/tsci220918046a","DOIUrl":"https://doi.org/10.2298/tsci220918046a","url":null,"abstract":"A new design of Solar Air Heater (SAH) with triangle cross-section is numerically studied. The thermal performance of SAH is studied at various mass flow rates, inlet air temperatures and solar irradiation intensities. The CFD model is developed using the software ?ANSYS Fluent? to study the fluid flow and heat transfer in the solar air heater. 3D discretization is applied to study the thermal performance of solar collector with triangle cross section. Mesh independence is performed in order to choose the adequate mesh. The discrete ordinate radiation model (DOM) and the RNG k-? turbulence model are used to study the radiative heat transfer and the turbulent flow inside the SAH. Particularly, effects of different internal peak angles (145?,126?, 100?, 80? and 67.5?) under different solar irradiation intensities (from 620W/m^2 to 1081W/m^2) are studied to improve the thermal performance of the SAH. The results show a good agreement between the numerical model and the experimental data with an average error of 6%. The maximum outlet air temperature of the SAH reached 72?C for the geometries with 12 and 16 channels (Internal peak angles of 80? and 67.5?, respectively) under mass flow rate of 0.0264kg/s. The thermal performances of the SAH with 16 and 12 channels are 24.2% higher than standard geometry, respectively for solar irradiation intensity of 1081 W/m^2. The configuration with internal peak angle of 80? and 12 channels is selected as the optimal with a thermal efficiency of 79%, a low pressure drops compared to geometry with 16 channels and lower costs.","PeriodicalId":23125,"journal":{"name":"Thermal Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68248307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Flame and emission characteristics from NH3/CH4 combustion under ultrasonic excitation 超声波激励下NH3/CH4燃烧火焰及发射特性

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci221008029s

Yi Su, Yifeng Chen, Chunjie Sui, Tianjiao bi, Wei Chen, Bin Zhang

{"title":"Flame and emission characteristics from NH3/CH4 combustion under ultrasonic excitation","authors":"Yi Su, Yifeng Chen, Chunjie Sui, Tianjiao bi, Wei Chen, Bin Zhang","doi":"10.2298/tsci221008029s","DOIUrl":"https://doi.org/10.2298/tsci221008029s","url":null,"abstract":"As a high energy density hydrogen-rich carrier, ammonia (NH3) is a highly promising carbon-free fuel. The large-scale industrial application of NH3 is limited by its low reactivity and high nitrogen oxide (NOX) emission. In this work, the flame and emission characteristics of ammonia/methane (NH3/CH4) non-premixed combustion were investigated under ultrasonic excitation. An experimental system was designed and built, including non-premixed combustion system, loading ultrasonic system, deflection tomography temperature measurement system and flue gas measurement system. Combustion and measurement experiments at different ultrasonic frequencies and NH3/CH4 blending ratios were carried out. Flame images and flue gas species concentrations under ultrasonic excitation were acquired. The 3D temperature field was reconstructed. The influence of ultrasonic excitation at different frequencies on flame characteristics, flame temperature field and emission characteristics of the combustion process was analysed. The mechanism of NH3/CH4 combustion enhancement and emission reduction was revealed when the flame was excited by ultrasonic waves. Results showed that part of the hydrocarbon fuels was replaced by NH3 to reduce carbon dioxide (CO2) emission. The height and colour of the NH3/CH4 flame were changed and the high-temperature area of the flame gradually expanded as ultrasonic acted on the flame. As ultrasonic frequency increased, the emission concentrations of unburned CH4, unburned NH3 and NO decreased significantly. The flame was excited by ultrasonic waves, which reduced its local equivalent ratio, improved combustion efficiency and suppressed NOX generation.","PeriodicalId":23125,"journal":{"name":"Thermal Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68249102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Thermodynamic analysis and optimization design of cooling plate with multiple channels for linear synchronous motor 直线同步电机多通道冷却板的热力学分析与优化设计

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci221111053d

F. Du, Yang Bo, Tangjia Zhang

引用次数: 0

Special solutions for the Laplace and diffusion equations associated with the algebraic number field 与代数数场相关的拉普拉斯方程和扩散方程的特殊解

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci221113006y

Xiao-jun Yang, N. Sweilam, M. Bayram

引用次数: 0

The influence of temperature on geothermal power plant performance based on geology in Huangshadong geothermal field, China 基于地质的黄沙洞地热田温度对地热发电厂性能的影响

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci221215079l

C. Luo, Lichang Huang, Jiawei He, Huiwen Huang, S. Cai

引用次数: 0

The study of heat characteristics for micro pin-fin heat sinks with different structures 不同结构微鳍片散热器的热特性研究

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci230311175k

Nailiang Kuang, Guoran Lu, Kui Li, Yanmei Kong, Jiangbin Zheng, Binbin Jiao

{"title":"The study of heat characteristics for micro pin-fin heat sinks with different structures","authors":"Nailiang Kuang, Guoran Lu, Kui Li, Yanmei Kong, Jiangbin Zheng, Binbin Jiao","doi":"10.2298/tsci230311175k","DOIUrl":"https://doi.org/10.2298/tsci230311175k","url":null,"abstract":"Heat flux in electronic devices has increased dramatically with the development of advanced IC technology, facing the demand for effective thermal management technology. Micro pin-fin heat sink (MPFHS) has been demonstrated to be capable of improving the heat transfer capability and suppressing temperature rise effectively. In order to elaborate the discrepancy of heat dissipation of the MPFHS due to the cross-section shapes of pin-fin structures a set of heat sink samples with four different shapes, including the Circle-MPFHS, the Square-MPFHS, the Crisscross-MPFHS and the Octagon-MPFHS, are fabricated with micromachining technology. Then, the thermal characteristics are tested by integrating the heat sinks with a Pt film resistor chip as the heating source, and nucleate boiling phenomenon was observed with a high-speed camera. Results showed that concave corners in pin-fin structures increased the specific surface area, but generated low-velocity vortexes in back flow regions, reducing the heat transfer capability. The heat transfer coefficients of the Octagon-MPFHS, the Crisscross-MPFHS and the Circle-MPFHS was increased by 161.9 %, 152.4% and 85.7 % respectively relative to the Square-MPFHS at the flow rate of 147 kg/m2s. The heat transfer coefficients of the Octagon-MPFHS, the Crisscross-MPFHS, the Circle-MPFHS and the Square-MPFHS was increased by 7.27 %, 11.32 %, 2.56 % and 4.76 % when the mass flow rate was increased from 147 kg/m2?s to 295 kg/m2s. The nucleate boiling phenomenon in the Crisscross-MPFHS showed periodicity and positive feedback effect, resulting in local dry-out and consequent heat transfer capability deterioration. This study will contribute to the design and modification of MPFHS.","PeriodicalId":23125,"journal":{"name":"Thermal Science","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68261823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermodynamics of bacteria-phage interactions T4 and Lambda bacteriophages, and E. coli can coexist in natural ecosystems due to the ratio of their Gibbs energies of biosynthesis T4、Lambda噬菌体和大肠杆菌由于其生物合成吉布斯能的比例，可以在自然生态系统中共存

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci2301411p

M. Popovic

引用次数: 7

A variational principle for fractal Klein-Gordon equation 分形Klein-Gordon方程的变分原理

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci2303803c

Qiaoling Chen

引用次数: 0

Experimental study on heat transfer enhancement of heat storage material for energy pile 能量桩蓄热材料强化传热的实验研究

IF 1.7 4区工程技术

Thermal Science Pub Date : 2023-01-01 DOI: 10.2298/tsci2301591y

Jun Yan, Song Gao

引用次数: 0