{"title":"Experimental investigation of secondary flow effect caused by internal heat generation in the horizontal laminar pipe flow","authors":"Dong-Hyuk Park, Bum-Jin Chung","doi":"10.1016/j.applthermaleng.2025.128563","DOIUrl":null,"url":null,"abstract":"<div><div>In the Liquid-fueled Molten Salt Reactors (MSRs), the nuclear fuel is dissolved within the fluid, serving as the heat source and resulting in a non-homogeneous energy equation. Understanding the resulting thermal–hydraulic behavior is essential for the design and safety evaluation of MSRs. This study experimentally investigated laminar horizontal pipe flow with internal heat generation. Uniform volumetric heat generation was achieved by electrical dissipation of an H<sub>2</sub>SO<sub>4</sub> electrolyte solution. By varying the Reynolds number and heat generation rate, circumferential and axial wall temperature distributions were measured. The presence of internal heat generation led to elevated wall temperatures, attributed to low fluid velocity near the wall. These temperature gradients induced buoyancy forces, resulting in thermal stagnation in the top region of the pipe and the development of secondary flow beneath this region. This phenomenon contributed to localized hot spots on the top region and wall temperature reduction at the lower region. Based on the experimental data, empirical correlations for the dimensionless wall temperature were developed. To the best of our knowledge, this study presents the first experimental observation of secondary flow effects in internally heated horizontal laminar pipe flow.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"281 ","pages":"Article 128563"},"PeriodicalIF":6.9000,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Thermal Engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359431125031552","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
In the Liquid-fueled Molten Salt Reactors (MSRs), the nuclear fuel is dissolved within the fluid, serving as the heat source and resulting in a non-homogeneous energy equation. Understanding the resulting thermal–hydraulic behavior is essential for the design and safety evaluation of MSRs. This study experimentally investigated laminar horizontal pipe flow with internal heat generation. Uniform volumetric heat generation was achieved by electrical dissipation of an H2SO4 electrolyte solution. By varying the Reynolds number and heat generation rate, circumferential and axial wall temperature distributions were measured. The presence of internal heat generation led to elevated wall temperatures, attributed to low fluid velocity near the wall. These temperature gradients induced buoyancy forces, resulting in thermal stagnation in the top region of the pipe and the development of secondary flow beneath this region. This phenomenon contributed to localized hot spots on the top region and wall temperature reduction at the lower region. Based on the experimental data, empirical correlations for the dimensionless wall temperature were developed. To the best of our knowledge, this study presents the first experimental observation of secondary flow effects in internally heated horizontal laminar pipe flow.
期刊介绍:
Applied Thermal Engineering disseminates novel research related to the design, development and demonstration of components, devices, equipment, technologies and systems involving thermal processes for the production, storage, utilization and conservation of energy, with a focus on engineering application.
The journal publishes high-quality and high-impact Original Research Articles, Review Articles, Short Communications and Letters to the Editor on cutting-edge innovations in research, and recent advances or issues of interest to the thermal engineering community.