If air at 30 degree c Dry Bulb temp and water vapour content(Mw)=0.015kg/kg flows over a basin containing water at 10 degree C.

a) what will happen to the air temp?
b) what will happen to the moisture content in the air?
c) what will happen to the enthalpy of the air water vapour mixture?

a) When air at 30 degrees Celsius (dry bulb temperature) flows over a basin containing water at 10 degrees Celsius, the air temperature is expected to decrease. This is because heat transfer occurs from the higher temperature air to the lower temperature water in order to establish thermal equilibrium. As a result, the air temperature will decrease due to the heat exchange with the water.

b) The moisture content in the air, represented by the specific humidity (Mw), will most likely remain the same unless there is evaporation or condensation occurring in the system. However, the information provided does not specify whether there is any evaporation or condensation, so the moisture content may stay constant in this scenario.

c) The enthalpy of the air-water vapor mixture will decrease due to the heat transfer that occurs when the air flows over the cooler water. Enthalpy is related to the internal energy and temperature of the system, and the heat transfer from the warmer air to the cooler water will result in a decrease in the enthalpy of the air-water vapor mixture.

To answer these questions, we need to consider the principles of heat transfer and the behavior of air and water vapor mixtures. The relationship between temperature, humidity, and air-water vapor mixture properties can be analyzed using the psychrometric chart.

a) To determine what will happen to the air temperature, we need to understand the concept of sensible heat transfer. Sensible heat refers to the heat gained or lost by a substance without experiencing a phase change. In this case, the air at 30°C is flowing over water at 10°C.

Since the water temperature is lower than the air temperature, sensible heat transfer will occur from the air to the water, resulting in a decrease in air temperature. The amount of temperature change depends on factors like the flow rate, contact area, and specific heat capacities of air and water.

b) The moisture content in the air, known as humidity, can be affected by the temperature difference between the air and the water. In this scenario, as the air temperature decreases due to sensible heat transfer, the water vapor in the air may start to condense into liquid water.

The condensation process reduces the moisture content in the air, leading to a decrease in humidity. To determine the actual moisture content or humidity ratio of the air, calculations using the psychrometric chart or specific humidity equations may be needed.

c) The enthalpy of the air-water vapor mixture describes the total energy content of the mixture. It includes both sensible heat and latent heat (associated with phase changes, like the evaporation or condensation of water vapor).

In this case, as the air temperature decreases due to sensible heat transfer, the enthalpy of the air-water vapor mixture will also decrease. This is because the sensible heat lost by the air is equal to the decrease in enthalpy.

Again, the specific change in enthalpy depends on various factors, such as the flow rate, area of contact, and specific heat capacities of air and water. Precise calculations can be made using enthalpy calculations based on the properties of air and water vapor.

Overall, to obtain more accurate and detailed values for air temperature, humidity, and enthalpy, additional information and specific calculations may be required using psychrometric properties or equations related to air-water vapor mixtures.