Abstract: It is usually very difficult, if not impossible, to find the data needed in handbooks when calculating the Cp,m of gases at high temperatures. In this paper, a method of calculating the Cp,m of gases at high temperatures is pro-posed. By this method, firstly an extrapolation of temperature is made point by point, according to desired step of increase, starting from the upper limit of the temperature range given in the handbook; secondly, the data aresmoothed by employing the five points data smoothing method, and finally, a linear regression is carried out using the smoothed data points to obtain the Cp,m - T function: Cp,m = a₀ + a₁T + a₂T² +a₃T³ +a₄T⁴,which is then used to calculate the Cp,m of the gases at high temperatures. A comparison is made between the result obtained with this method and that obtained by using statistical thermodynamic method, and the two are very consistent.

Key words: Gases, High temperature, Extrapolation, Linear regression, Comparison