Measuring the coefficient of unit surface conductance of steel balls for frying without cooking oil by using dimensional analysis

International Conference on Sustainable Agriculture for Rural Development 2018

Siswantoro^1 ; Margiwiyatno, A.^1 ; Dwiyanti, H.^1

Department of Agricultural Technology, Faculty of Agriculture, Jenderal Soedirman University, Purwokerto, Indonesia^1

关键词: Dimensional analysis;    Dimensionless temperatures;    Direct contact;    Frying process;    Heat transfer process;    High temperature;    Laboratory experiments;    Surface conductance;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/250/1/012067/pdf
DOI  :  10.1088/1755-1315/250/1/012067

来源: IOP

【 摘 要 】

Frying process is basically exchange of thermal energy through direct contact between a transferring heat medium and the food in high temperature. Cooking oil is the most commonly used as frying medium, but there is an alternative frying process without cooking oil by using sand and steel balls. Even though frying process is a very popular, theory of the frying process was long neglected and poorly understood. In frying process, coefficient of unit surface conductance is an important thermal property for analyzing heat transfer process. A common notation used for the coefficient is h and the unit is J/s.m2.C. Objective of this research was to measure the coefficient of unit surface conductance (h) by using dimensional analysis for constructing mathematical model. Laboratory experiments were conducted to find the h of steel balls with various diameters. An aluminum plate was used to simulate food being fried. A cylindrical frying machine was employed for frying process. The h value was determined based on dimensionless temperature ratio. The h values were then used to develop an empirical mathematical model using dimensional analysis. The developed mathematical model showed a good agreement with measurement results with average of errors was less than 10%.