heat transfer coefficient
 

So I am interested in finding heat transfer coefficient in a cutting tool with a constant heat source(one small section at constant temperature) .The air is being flown over the tool at a speed of 1m/s. In the attached image one can see that a small cut face(I named it as nose section) is kept at constant temperature of 1057K. I have used the nose section as wall with constant temperature and all other interfaces that are coming in contact with air are taken as coupled walls.
Temperature distribution is being calculated correctly but contours of heat transfer coefficient are always showing zero. Also if using heat flux on nose face/(Ts-T∞) is giving abnormally high values. Is there a other method to calculate heat transfer coefficient? I think boundary condition at nose and its interface with fluid has some mistake!