The mucalc program gives the viscosities of our compounds as gases at low density:
function MU = mucalc (T,index) % Chapman-Enskog formula for viscosity of monatomic and polyatomic gases % % function MU = mucalc(T,index) % % Argument List: % T [=] temperature in the units of Tdeg % index [=] index of compounds in cnms whose viscosities are to be found % (If this argument is omitted, all viscosities will be found.) % Returns: % MU [=] viscosity in units of kg/m/s % % Ex: >> clear % >> start402 % >> mu = mucalc(298, 1) % mu = % 0.2296e-04 Created 3/21/95-2 Jim Lee global mw lenjones lj = checklj; M=mw'; T=at(T); if nargin==1 [omega_mu k D] = omegacalc(T./lj(:,2)); MU = 2.6693e-6 * sqrt(M*T) ./ (lj(:,1).^2.*omega_mu); else [omega_mu k D] = omegacalc(T./lj(index,2)); MU = 2.6693e-6 * sqrt(M(index)*T) ./ (lj(index,1).^2.*omega_mu); end % This file was created by m2html.
We can compare the results of this program with values determined by BS&L and shown in their Examples 1.4-1 and 1.4-2. After setting arrays for CO2, O2, N2 and Ne with start301.
>>mucalc(200,1) ans = 1.0137e-05 <-- BS&L gave 1.013e-05 (calc.) and 1.015e-05 (exp.) >>mucalc(300,1) ans = 1.4937e-05 <-- BS&L gave 1.494e-05 (calc.) and 1.495e-05 (exp.) >>mucalc(800,1) ans = 3.2691e-05 <-- BS&L gave 3.269e-05 (calc.) >>mucalc(293,1:3) ans = 1.0e-04 * 0.1462 <-- BS&L gave 1.462e-05 (calc.) for CO2 0.2027 <-- BS&L gave 2.031e-05 (calc.) for O2 0.1747 <-- BS&L gave 1.754e-05 (calc.) for N2
Note that the units reported by BS&L are g/cm/s, while those returned by the function are SI: kg/m/s.
The mixmu function gives the viscosity of a gas mixture:
function mu=mixmu(zs,T,j) % mixmu(zs,T,j) finds the viscosity of a low density gas mixture % zs gives the mol fraction of each compound % T gives the temperature in the units of Tdeg % j gives the indices of the compounds (if missing it includes % all compounds. zs must be consistent with j. % Based on equations 1.4-19 and 20 in BS&L % The viscosity is given in kg/m/s global mw if nargin<3 j=1:length(mw); end [phi,mus]=mixphi(T,j); den=phi*zs'; mu=zs*(mus./den); % This file was created by m2html.
Here is a comparison with example 1.4-2 in BS&L:
>>mixmu([0.133 0.039 0.828],293,1:3) ans = 1.7084e-05 <--BS&L found 1.714e-05