Consider pressurized water, engine oil (unused), and NaK (22%/78%) flowing in a 20-mm-diameter tube. (a) Determine the mean velocity, the hydrodynamic entry length, and the thermal entry length for each of the fluids when the fluid temperature is 366 K and the flow rate is 0.01 kg/s. (b) Determine the mass flow rate, the hydrodynamic entry length, and the thermal entry length for water and engine oil at 300 and 400 K and a mean velocity of 0.02 m/s.

Lecture 6: Dimensions and Units Outcomes Explain the difference between units and dimensions List the base (fundamental) dimensions in the SI system Identify derived dimensions and units Perform dimensional homogeneity checks on equations Explain the concept and use of dimensionless numbers Use common prefixes and prefix symbols o Table 2.6 on page 28 in text Dimensions vs units Dimensions o Used to describe or specify the nature of physical quantities o There are base and derived dimensions o Dimensions are independent of units o Examples: length, mass, force, velocity, voltage Units o Standard measure of the magnitude of a dimension with a predet