Passive Ice Protection for Electrically Powered Vehicles: Preliminary ANSYS Computational Fluid Dynamics Result
From Kenjiro Lay on July 26th, 2020
This research investigates a novel method of ice protection specifically for electrically powered motor which is semi-passive, requiring almost no additional power. By encasing the motor coils, which are capable of reaching temperatures in excess of 250 °C, in a hollow cavity, the rotor downwash will be unable to cool the motor. Cool air will flow over the coils through an intake valve on the motor where the motor cavity will be connected to a channel in the leading edge of the rotor; through centrifugal pumping, the warm air from the motor will enter the leading-edge channel, warming the rotor surface. The inefficiencies of the motor will heat the air in the insulated cavity. Here, we simulate flow of warm air through the leading-edge cavity (15% and 25% of the upper and lower surfaces, respectively) of an NACA 0012 airfoil with a chord length of 1-inch and span of 12-inch. The airfoil is cooled convectively with coefficient of heat transfer of 10 W/(K-m2). Fluid flow was modeled using realizable K-Epsilon turbulent model and calculation was done until it converged and steady state solution was achieved. Various variables such as flow velocity, flow temperature, and environmental temperature were tested. Assuming air and wall temperature to be equal, preliminary computational fluid dynamic using ANSYS shows that this semi-passive approach would maintain the blades above freezing. When subjected to a flow velocity of 15 m/s, flow temperature of 60 °C and environmental temperature of -16 °C, blade temperature is shown to be above 2°C.