A new and reliable model for predicting methane viscosity at high pressures and high temperatures

On the isobaric specific heat capacity of natural gas

“…To keep the pressure constant, it was necessary to let the cell open and continuously increase the volume of the whole system. This was done by connecting the line from the measuring cell to a cylinder with a piston (pressureregulation system) [25].…”

A smooth model for the estimation of gas/vapor viscosity of hydrocarbon fluids

“…Genetic programming based model for calculating the pure and hydrocarbon gas mixtures viscosity was used by Shokir and Dmour [2] . Heidaryan et al [18] proposed a correlation for calculation of methane viscosity as a function of reduced pressure and temperature (Heidaryan A). Heidryan et al [19] also developed a correlation for gas viscosity prediction based on molecular weight, temperature and gas density.…”

“…It can be concluded fromTable 2that the proposed GEP model, having correlations significantly. Also, it can be concluded that Heidarian A and B correlations[18,19] show the largest scattering among the correlations, while the GEP model has the least dispersion and scattering around the zero error lines. From average percent relative error and…”

“…The fitness values decrease as a result of an increase in generation numbers[39]. In this study, the optimal fitness for Eq.3 was occurred in 14 th run at the 920 th generation.After developing the model, we have compared GEP model with twelve of the most well-known existing correlations including: Heidarian A[18], Heidarian B[19], Lee et alGraphical error analyses including cross plot and error distribution have been utilized as well as Statistical error analysis including: average percent relative error, standard deviation, and average absolute percent relative error. It should be noted that a large databank with the data being in limited ranges does not guarantee a good prediction as we can see it in the case of…”

Review on Natural Gas Thermopysical Property Measurement Techniques

“…In most cases the viscometer arrangement is vertical, which is a serious limitation for gas measurements considering the very short travelling times. Heidaryan et al [49] used a falling body viscometer for measuring methane viscosity up to 140 MPa.…”