A Professor of Fluid Mechanics a told that the static temperature is the temperature observed when the relative speed between observer(thermometer) and fluid is zero. I have trouble understanding as to how will the temperature of fluid depend on the reference frame since temperature is a quantity which should be a function of Static Pressure and not Pressure itself. How can the temperature of a body depend on its speed?
Moving fluid has kinetic energy which will be converted to internal energy if the flow changes. This is straight-up first law.
So you might consider air blowing through a venturi for instance; if you were to insert a thermometer at different points along the airflow, you would measure different temperatures as the airflow accelerates and decelerates.