Chapter 12, Problem 20P

Table 12-1 gives the Seireg and Dandage curve fit approximation for the absolute viscosity in customary U.S. engineering units. Show that in SI units of mPa · s and a temperature of C degrees Celsius, the viscosity can be expressed as

$\mu =6.89\left({10}^6\right){\mu }_{0}exp\left[\left(b/\left(1.8C+127\right)\right)\right]$

where μ₀ and b are from Table 12-1. If the viscosity ${\mu }_0^{\text{'}}$ is expressed in μ reyn, then

$\mu =6.89{\mu }_0^{\text{'}}\text{ exp}\left[\left(b/\left(1.8C+127\right)\right)\right]$

What is the viscosity of a grade 50 oil at 70°C? Compare your results with Fig. 12-13.