{"title":"Study of Fluid Motions and Thermal Performance of Water and Acetone Oscillating Heat Pipes using Neutron Imaging","authors":"Il Yoon, Robert Winholtz, Hongbin Ma","doi":"10.1615/heattransres.2023049240","DOIUrl":null,"url":null,"abstract":"Quantitative analysis of fluid motion in an oscillating heat pipe (OHP) is essential to better un-derstand fluid flow and heat transfer mechanisms in an oscillating heat pipe. Two copper oscillat-ing heat pipes filling with water and acetone respectively were investigated by a neutron imaging technique to visualize the fluid motions in the oscillating heat pipes. Temperatures on the surface of the oscillating heat pipes were measured while neutron images were taken simultaneously. Al-gorithms to determine the degree of activity and the interface passing count were developed to analyze fluid motions quantitatively from the neutron images. Then, the degree of activity and the interface passing count were compared with temperatures. The results showed that there are patterns of temperature change before and after start-up of the oscillation motions. The acetone oscillating heat pipe showed better thermal performance at a similar heat input, while the water oscillating heat pipe showed better thermal performance at a similar degree of activity. Interfaces in the acetone oscillating heat pipe oscillate more frequently and travel further. A virtuous circle is formed between sensible heat transfer and latent heat transfer for better thermal performance. Low latent heat at low heat input, low viscosity and high thermal conductivity are preferred for the working fluid to achieve better thermal performance.","PeriodicalId":50408,"journal":{"name":"Heat Transfer Research","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Heat Transfer Research","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1615/heattransres.2023049240","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"THERMODYNAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Quantitative analysis of fluid motion in an oscillating heat pipe (OHP) is essential to better un-derstand fluid flow and heat transfer mechanisms in an oscillating heat pipe. Two copper oscillat-ing heat pipes filling with water and acetone respectively were investigated by a neutron imaging technique to visualize the fluid motions in the oscillating heat pipes. Temperatures on the surface of the oscillating heat pipes were measured while neutron images were taken simultaneously. Al-gorithms to determine the degree of activity and the interface passing count were developed to analyze fluid motions quantitatively from the neutron images. Then, the degree of activity and the interface passing count were compared with temperatures. The results showed that there are patterns of temperature change before and after start-up of the oscillation motions. The acetone oscillating heat pipe showed better thermal performance at a similar heat input, while the water oscillating heat pipe showed better thermal performance at a similar degree of activity. Interfaces in the acetone oscillating heat pipe oscillate more frequently and travel further. A virtuous circle is formed between sensible heat transfer and latent heat transfer for better thermal performance. Low latent heat at low heat input, low viscosity and high thermal conductivity are preferred for the working fluid to achieve better thermal performance.
期刊介绍:
Heat Transfer Research (ISSN1064-2285) presents archived theoretical, applied, and experimental papers selected globally. Selected papers from technical conference proceedings and academic laboratory reports are also published. Papers are selected and reviewed by a group of expert associate editors, guided by a distinguished advisory board, and represent the best of current work in the field. Heat Transfer Research is published under an exclusive license to Begell House, Inc., in full compliance with the International Copyright Convention. Subjects covered in Heat Transfer Research encompass the entire field of heat transfer and relevant areas of fluid dynamics, including conduction, convection and radiation, phase change phenomena including boiling and solidification, heat exchanger design and testing, heat transfer in nuclear reactors, mass transfer, geothermal heat recovery, multi-scale heat transfer, heat and mass transfer in alternative energy systems, and thermophysical properties of materials.