High-Temperature Viscosity Ratios for Hydrogen, Helium, Argon, and Nitrogen

Abstract

The temperature dependency of the coefficient of viscosity relative to its value at 283°K has been determined for hydrogen, helium, argon, and nitrogen at atmospheric pressure. The method used is a variation of the usual capillary viscometry scheme in that no attempt is made to obtain absolute viscosity values. The measurements provide the ratio of the viscosity of a gas at temperature T to its viscosity at the reference temperature, 283°K. The value of T ranges from 1100°K to 2150°K and is measured by a disappearing filament pyrometer. In this relative method there is cancellation of most noncontrolled experimental variables so that the measurements are of high reproducibility, ±0.1%, and apparently accuracy, ±0.4%, is limited only by the uncertainties in the international temperature scale in the optical pyrometer range. These results are higher by 3%-8% compared with the results of previous workers. However, extrapolation of lower-temperature viscosity measurements by Kestin and Leidenfrost, and more recently by DiPippo, gives excellent agreement with the values reported here.

Ab initiopotential energy curve for the helium atom pair and thermophysical properties of the dilute helium gas. II. Thermophysical standard values for low-density helium

“…These systematic deviations are a consequence of a temperature measurement error with thermocouples extensively discussed by Vogel et al [69] and are still relatively small for helium due to the large thermal conductivity coefficient compared with those of other common gases. The relative measurements of Guevara et al [66] and of Dawe and Smith [67] with capillary viscometers based on a reasonable calibration at room temperature make obvious that they are influenced by systematic errors and that the theoretical calculation is distinctly superior to the experiment at these high temperatures. Figure 8 displays the deviations of the experimental viscosity data by Becker et al [57] and Becker and Misenta [58] from the theoretically calculated values for 3 He.…”

On the utility of the m-6-8 potential function

“…Solutions of eq (13) for argon at several experimental temperatures as in figure 3. Note the very small area given by the 11-6-8 with Y = 3.0 29 5. Continuation of figure 4.…”

“…Solutions of eq (13) for argon at several exper innental temperatures for the m-6 potential function. Note the "turn around," with respect to temperature, of the solutions at 129.…”

“…, scaled by r , but it is frequentlymore convenient to work in terms of the effective hard sphere diameter, a, defined by where we have defined f^l^(r=;=) as l(r*)/e. Potentials (8) and (10) In eqs (11) and (12) Data : The argon data selected for test purposes [12] were extracted from the following sources: viscosity [13][14][15][16] In a previous paper [2] we mentioned another graphical and interpolation scheme whereby a simultaneous fit of the viscosity and second virial coefficient for a given gas could be used to give potential parameters and which would, at the same time, demonstrate how the fit was modified as the parameters change. This discussion is repeated briefly here.…”

“…Percentage deviation plot of experimental dilute gas viscosity coefficients of argon compared to theoretical values determined from eq (11) with the m-6-8 potential: m = 11, y = 3.0, a = 3.292 A, e/k = 153 K. Data [13], A [14], n [15], v [16], 0 [19], # [20], [21]; not distinguished [22,23] 32 8. Percentage deviation plot of experimental dilute gas thermial conductivity coefficients for argon compared to eq (14) with the m- [44] .…”