For laminar boundary layers it is reasonable to expect that / t Pr n , where

For laminar boundary layers it is reasonable to expect that δ/δ_t ≈ Prⁿ, where n is a positive exponent. Consider laminar boundary layer flow over a flat plate with air at 100ºC and 1 atm, the thermal boundary layer thickness is approximately 15% larger than the velocity boundary layer thickness. Determine the ratio of δ/δt if the fluid is engine oil (unused) under the same flow conditions.