The Impact of the Fourier Number on Calculation Accuracy of Transient Heat Transfer in Homogeneous Enclosures

  • Darius PUPEIKIS Kaunas University of Technology
  • Lina ŠEDUIKYTĖ Kaunas University of Technology
  • Patrikas BRUZGEVIČIUS Kaunas University of Technology
Keywords: transient heat transfer, transient heat exchanges, Fourier number, homogeneous enclosure


Transient heat transfer can be characterized by the concept of heat transfer when heated (cooled) material’s temperature varies continuously in time. Usually, transient heat transfer is calculating according to finite element method. The great impact on the accuracy of calculation has a criteria of similarity, which is also known as Fourier number. This number shows the similarity of thermal variation in conditional layers of enclosures. Most scientists recommend to use 0.5 value of Fourier number and perform calculating of an transient heat transfer in all cases.
This paper introduces the results of experimental research of transient heat transfer in homogeneous building materials. Moreover, to compare the results of experimental research, transient heat transfer spreadsheet was created. Our research has shown that 0.5 value of Fourier number for calculations of transient heat transfer in homogeneous building materials is acceptable.