QUESTION 3 Figure 3 shows the initial state of a system. Container A of 1 m3 contains Air at 300 K and 1500 kPa. It is connected through a valve to a piston-cylinder B with a cross-sectional area of 0.1 m2. When the valve is opened, the piston of cylinder B slowly rises to a height of 2 m. During this process, the air temperature is kept constant at 300 K and it is possible to assume that the entire system (pond + cylinder) expands from a volume VA to a volume (VA + VB). Determine: a) For the initial conditions of pressure and temperature, can the behavior of air be considered as an ideal gas? Foundation. b) What is the change in internal energy in containers A and B during the process? c) The final pressure in cylinder B when the valve is closed.

Steam flows in a Schedule 40, 6" (NPS) nominal pipe size 1000 ft long pipe, with roughness 45 micron. The steam enters the pipe at 200 oC. The steam flow rate is 45,000 lb/hr and the pressure at the entrance of the pipe is 10 bar. The pipe is well insulated and the flow of steam is considered isothermal. Assume that the steam behaves as an ideal gas with constant viscosity 0.018 cp. The molecular weight of steam is Mw=18 kg/kmol. Calculate the pressure of the steam at the outlet of the pipe (in bar)

Thermal systems problem: Assume that nitrogen is available in a storage tank at 2 MPa and 210 K. On the following chart, show the path for the following scenarios. a) An expansion valve is connected to this tank that drops the fluid (i.e., nitrogen) pressure at its outlet to one atmosphere.   b) A compressor is connected to this tank that raises the fluid pressure at its outlet to 10 MPa.   c) A turbine is connected to this tank that drops the fluid pressure at its outlet to one atmospheric pressure. d) A heat exchanger is connected to this tank that raises the fluid temperature to 330K at its outlet. e) A heat exchanger is connected to this tank that drops the fluid temperature to 135K at its outlet.   f) Show the process for the fluid to change its state from 2 MPa and 210 K to 14 MPa and 240 K.  Identify the required equipment. g) If a coolant at 150 K is available, is it possible to change the state of nitrogen from 2 MPa and 210 K to saturated liquid at atmospheric pressure?  If…

PROBLEM 3 Saturated water vapor at 100 kPa is in a piston-cylinder device. At the initial state the piston is 0.2 m from the cylinder bottom. The water vapor is heated in a constant pressure process until the cylinder volume is doubled. Sketch this process on P-v and T-v diagrams. Find the final distance from the piston to the cylinder bottom and the final temperature.

A person is trying to keep cool on a hot summer day by using a fan and exposing his/her body to air flow. The air temperature is To = 32°C, and the fan is blowing air at a velocity of vo = 5 m/s. The surrounding surfaces are at Tsur = 40°C, and the emissivity of the person can be taken as ɛ = 0.9. If the person is doing light work and generating sensible heat at a rate of 90 W, determine the average temperature of the outer surface of the person. The average human body can be treated as a 30-cm diameter cylinder with an exposed surface area of 1.7 m?.

Problem 3-64 A piston-cylinder device initially contains steam at 3.5 MPa, superheated by 5°C. Now, steam loses heat to the surroundings and the piston moves down, hitting a set of stops, at which point the cylinder contains saturated liquid water. The cooling continues until the cylinder contains water at 200°C. Determine (a) the initial temperature, (b) the enthalpy change per unit mass of the steam by the time the piston first hits the stops, and (c) the final pressure and the quality (if mixture). Steam 3.5 MPa 69 F Partly cloudy

(5)An insulated piston-cylinder device contains 15 L of saturated liquid water at a constant pressure of 950 kPa. Water is stirred by a paddle wheel while a current of 15 A flows for 28 min through a resistor placed in the water. If 64% of the liquid is evaporated during this constant pressure process and the paddle-wheel work amounts to 600 kJ, determine the voltage of the source. Also, show the process on a P-v diagram with respect to saturation lines. H,0 P= constant W. W.

Water is boiled at sea level in a coffeemaker equipped with an immersion-type electric heating element. The coffeemaker contains 1L of water when full. Once boiling starts, it is observed that half of the water in the coffeemaker evaporates in 13 min. Determine the power rating of the electric heating element immersed in water. Also, determine how long it will take for this heater to raise the temperature of 1 L of cold water from 18°C to the boiling temperature.

An insulated, vertical piston–cylinder device initially contains 15 kg of water, 10 kg of which is in the vapor phase. Initially the pressure is 200 kPa inside the cylinder. A linear spring is connected to the piston therefore the pressure changes linearly with volume (P = m*v+b). Super heated steam at 0.5 MPa and constant temperature is allowed to enter the cylinder from a supply line until all the liquid in the cylinder has just vaporized and the pressure and volume in the cylinder have both doubled.   Determine the final temperature (in ºC) in the cylinder.  Determine the mass of the steam that has entered during this process. Determine the boundary work (in kJ) associated with the system during this process Determine the specific enthalpy (in kJ/kg) of the steam entering the cylinder.

8. 1.8-m³ rigid tank contains steam at 220 °C. One-third of the volume is in the liquid phase and the rest is in the vapor form. Determine (a) the pressure of the steam, (b) the quality of the saturated mixture, and (c) the density of the mixture.