I am simulating 2D Heat pipe which is divided into three part , evaporator, adiabatic section, condenser. I have don simulation in which water is converted into vapor in condenser section. Heat rejected from condenser is given to coolant water. Because of this temperature of condenser is decreasing in experiment. while simulating only heat pipe in ansys fluent, I am getting constant condenser temperature which is equal to saturation temperature. I have not simulated coolant water around condenser in Fluent. Is it required to simulate water around condenser in 2D or just I have to give heat transfer coefficient from condenser wall to water?