srakavermont.blogg.se - Dynamic viscosity formula

Dynamic viscosity formula full#

At 15 ☌, the viscosity of air is 1.81 × 10-5 kg/(m The viscosity of air depends mostly on the temperature. Inkjet printing, protein formulations and injections, and even food and beverage production all benefit from the viscosity law.įrequently Asked Questions 1. Water, for example, has a low or “thin” viscosity, but honey has a “thick” or “high” viscosity. Some Examples of viscosity Or viscous substances are honey, oil, toothpaste, and some chemical elements such as mercury. The unit of dynamic viscosity μ is centipoise. Dynamic viscosity is related to kinematic viscosity by the equation μ = ρv where ρ is the density of the fluid. Gas viscosity is often lower than liquid viscosity. The viscosity coefficient is a measurement of the fluid’s resistance to flow. The relationship between viscous and inertial forces in a fluid is known as kinematic viscosity. The relationship between shear stress and shear rate in a fluid is known as dynamic viscosity. SPE-1340-PA.Kinematic and dynamic viscosity are the two types of viscosity that are usually reported. Gases and Vapors At High Temperature and Pressure - Density of Hydrocarbon. Hydrocarbon Processing 51 (May): 119–122. Presented at the SPE Annual Technical Conference and Exhibition, Houston, 3–6 October. Compressibility Factors for Naturally Occurring Petroleum Gases (1993 version). Presented at the SPE Annual Technical Conference and Exhibition, Las Vegas, Nevada, USA, 22-26 September. Compressibility Factors for High-Molecular-Weight Reservoir Gases. Viscosity of Hydrocarbon Gases Under Pressure.

s by dividing by 1,000.Ĭalculate the viscosity at 150☏ (609.67°R) and 2,012 psia for the gas of the composition shown in Table 1.

This viscosity unit (cp) is also easily converted to the SI unit of Pa were originally written to give the viscosity in micropoise, but the modified form above gives the viscosity in the more commonly used centipoise. In using these equations, it is important either to measure the density or to ensure that the z -factor calculation has included the effect of N 2, CO 2, and H 2S using the method of Wichert and Aziz.

M g = gas molecular weight = 28.967 γ gįor the data from which the correlation was developed, the standard deviation in the calculated gas viscosity was 2.7%, and the maximum deviation was 9%.

are for specific units as noted below and are as follows: The method uses the gas temperature, pressure, z factor, and molecular weight, which have to be measured or calculated the density can be measured or calculated as well. This method lends itself for use in computer programs and spreadsheets. developed a useful analytical method that gives a good estimate of gas viscosity for most natural gases.

5 – Pseudocritical properties of methane-based natural gases (from Sutton ). 2 are corrections to be added to the atmospheric viscosity when the gas contains N 2, CO 2, and H 2S.įig. If only specific gravity is known, then the pseudocritical properties would have to be obtained from Fig.

Dynamic viscosity formula full#

However, Kay’s rules require a full gas composition. to calculate the pseudocritical properties for use with those charts. It would not be correct, then, to use the methods of Sutton or Piper et al. ) are based on pseudocritical properties determined with Kay’s rules. 4) to obtain the viscosity at reservoir temperature and pressure. This viscosity is then multiplied by the viscosity ratio (from Fig.

N = number of components in the gas mixture.

M gi = molecular weight of the ith component of the gas mixture.

μ i = viscosity of the ith component of the gas mixture at the desired temperature and atmospheric pressure (obtained from Fig.

y i = mole fraction of the ith component.

μ ga = viscosity of the gas mixture at the desired temperature and atmospheric pressure.

2 or determined from the gas-mixture composition with Eq. The viscosity of gas mixtures at one atmosphere and reservoir temperature can either be read from Fig. 4 – Effect of temperature and pressure on viscosity of natural gases (from Carr et al.