I have below tank partailly filled with water and i want to make simulation in solidworks flow simulation to observe the temperature rise of the water after one week. I have set the tank outside wall temperature 30 ℃　and my problem is I cannot select the blue part of water and set as liquid. and I also want to consider the natural convection pheomenon at air and water interface. How can i model air and water as seperate liquid in solidworks?