I'd like to simulate a tube which has a water mass flow rate 0.21 kg/s and inlet temp is 340K. also there is a cross flow air over the tube externaly whose temp initialy is 288 K and velocity 20m/s. Thus I wanna see the fluid temp distribution thorugh the tube but i cant simulute that. I choose external flow analys and insert fluid subdomain as water in tube. also specify the tube material as aliminum. after i calculated i get the uniform 340K temp inside the tube. Pls can u help me about this ?