At a climate station, the surface air pressure is 101.1 kPa, air te temperature 20°C. Calculate...
Air pressure = 100 kPa Air temperature = 20 deg Wet-bulb (Dew Point) temperature = 16 degC Find: - Vapor pressure - Relative humidity, - Specific humidity, - Air density
An air parcel that has a temperature of 20 C and a dewpoint of 10 C at sea-level is forced to rise over a mountain that is 3 km high. Given the the appropriate MOIST ADIABATIC LAPSE rate is 5C/km, what would the temperature (in Celsius) of the air parcel be when it reaches the top of the mountain
The air in a room is at 25 °C and a total pressure of 101.325 kPa . Air contains water vapor with a partial pressure of 1.76 kPa. a. Calculate the air humidity and relative humidity. b. Since you intend to use this air for drying fre sh fruits you plan to heat up the air to 50°C. Once you accomplish that, what would be the new relative humidity of the air if the moisture content is maintained? c. Intuitively...
(20%) Q2. A piston-cylinder assembly initially has 100 kPa pressure and 2 liters of air at 25°C. The air is then compressed to 600 kPa pressure and 150°C temperature. Useful work input for compression is 1.2 kJ. Assuming that the ambient pressure and temperature are 100 kPa and 25°C respectively, calculate a) the exergy of the air in the first and last states, b) the minimum work required for the compression process, c) the second law efficiency of the state...
Example 5: Ambient air at 38°C db-temperature and 20°C wb- temperature enters an evaporative cooler with a dry air mass flow rate of 0.75 kg/s. The pressure is constant at 95 kPa. The air leaves at a db-temperature of 25°C. Calculate (i) the relative humidity of the air at inlet, (ii) the relative humidity of the air at exit, (iii) the rate of flow of water to the cooler, and (iv) the saturation effectiveness of the cooler.
Air enters an adiabatic nozzle under the following conditions: pressure = 900 kPa temperature = 560°C velocity = 2.7 m/s The air leaves the nozzle at 850 kPa and 480 °C. What is the velocity at the exit of the nozzle? Assume the specific heat is constant and can be taken at the average temperature between the inlet and outlet. air (c) EYES Niel Crews, 2013
2. Air enters an adiabatic nozzle with a pressure, temperature, and velocity of 900 kPa 500°C, and 2.8 m/s, respectively. The air leaves the nozzle at 850 kPa and 480°C. What is the velocity at the exit of the nozzle? Ans 208.949 m/s 2. Air enters an adiabatic nozzle with a pressure, temperature, and velocity of 900 kPa 500°C, and 2.8 m/s, respectively. The air leaves the nozzle at 850 kPa and 480°C. What is the velocity at the exit...
10-kg moist air at the temperature of 24°C, the pressure of 100 kPa, and relative humidity of 90% is enclosed in a cylinder and piston assembly. The enclosed air is cooled down to the temperature of 12°C at a constant pressure process (when piston can move freely). Determine a) at what temperature vapor starts to condense and b) the mass of condensed water during the process using the psychrometric chart.
1. (relative humidity) The partial pressure of water vapor in air is usually less than the equilibrium vapor pressure (or saturation pressure) at the ambient temperature; this is why a cup of water will spontaneously evaporate. The ratio of the partial pressure of water vapor to the equilibrium vapor pressure (at the same temperature) is called the relative humidity. Saturated air, at 100% relative humidity, would be in equilibrium with a cup of liquid water. The saturation pressure depends strongly...
Air enters an adiabatic nozzle at 500 kPa and a temperature of 200 °C with a velocity of 100 m/s. It exits the nozzle at a pressure of 100 kPa. Assuming that the expansion through the nozzle occurs reversibly, determine (a) the exit temperature and (b) the exit velocity of the air. The specific heats of air can be assumed to be constant with Cv = 0.742 kJ/kg oC and Cp = 1.029 kJ/kg oC.