What is the relationship between compressor work and COPR?

Why would the shear stress be considered as the momentum flux.

oksano4ka [1.4K]

Answer:

A fluid flowing along a flat plate will stick to it at the point of contact

Explanation:

and this is known as the no-slip condition. ... This is the precise reason why shear stress in a fluid can also be interpreted as the flux of momentum.

3 0

2 years ago

Steam enters a turbine at 8000 kPa, 440oC. At the exit, the pressure and quality are 150 kPa and 0.19, respectively.

levacccp [35]

Answer:

$\dot W_{out} = 3863.98\,kW$

Explanation:

The turbine at steady-state is modelled after the First Law of Thermodynamics:

$-\dot Q_{out} -\dot W_{out} + \dot m \cdot (h_{in}-h_{out}) = 0$

The specific enthalpies at inlet and outlet are, respectively:

Inlet (Superheated Steam)

$h_{in} = 3353.1\,\frac{kJ}{kg}$

Outlet (Liquid-Vapor Mixture)

$h_{out} = 890.1\,\frac{kJ}{kg}$

The power produced by the turbine is:

$\dot W_{out}=-\dot Q_{out} + \dot m \cdot (h_{in}-h_{out})$

$\dot W_{out} = -2.93\,kW + (1.57\,\frac{kg}{s} )\cdot (3353.1\,\frac{kJ}{kg} - 890.1\,\frac{kJ}{kg} )$

$\dot W_{out} = 3863.98\,kW$

8 0

3 years ago

What's the relationship between energy and time<br>

boyakko [2]

Answer:

The relationship between power, energy, and time can be described by the following equation : P = Δ E s y s Δ t. P is the average power output, measured in watts (W) ΔEsys is the net change in energy of the system in joules (J) - also known as work. Δt is the duration - how long the energy use takes - measured in seconds (s).

Explanation:

8 0

3 years ago

Write a GUI-based program that plays a guess-the-number game in which the roles of the computer and the user are the reverse of

AURORKA [14]

Answer:

import javax.swing.*;

import java.awt.*;

import java.util.Random;

import java.awt.event.*;

public class Guess extends JFrame

{

private static final long serialVersionUID = 1L;

private JButton newGame;

private JButton enter;

private JButton exit;

private JTextField guess;

private JLabel initialTextLabel;

private JLabel enterLabel;

private JLabel userMessageLabel;

private int randNum;

private int userInput;

private int maxtries = 0;

public Guess()

{

super("Guessing Game");

newGame = new JButton("New Game");

exit = new JButton("Exit Game");

enter = new JButton("Enter");

guess = new JTextField(4);

initialTextLabel = new JLabel("I'm thinking of a number between 1 and 100. Guess it!");

enterLabel = new JLabel("Enter your guess.");

userMessageLabel = new JLabel("");

randNum = new Random().nextInt(100) + 1;

setLayout(new FlowLayout());

add(initialTextLabel);

add(enterLabel);

add(guess);

add(newGame);

add(enter);

add(exit);

add(userMessageLabel);

setSize(500, 300);

addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{

System.exit(0);

}

});

newGameButtonHandler nghandler = new newGameButtonHandler();

newGame.addActionListener(nghandler);

ExitButtonHandler exithandler = new ExitButtonHandler();

exit.addActionListener(exithandler);

enterButtonHandler enterhandler = new enterButtonHandler();

enter.addActionListener(enterhandler);

}

class newGameButtonHandler implements ActionListener

{

public void actionPerformed(ActionEvent e)

{

setBackground(Color.ORANGE);

guess.setEnabled(true);

guess.setText("");

enter.setEnabled(true);

maxtries = 0;

userMessageLabel.setText("");

randNum = new Random().nextInt(100) + 1;

}

class ExitButtonHandler implements ActionListener

{

public void actionPerformed(ActionEvent e)

{

System.exit(0);

}

class enterButtonHandler implements ActionListener

{

public void actionPerformed(ActionEvent e)

{

userInput = Integer.parseInt(guess.getText());

checkGuess(randNum);

if(userInput > 100 )

{

userMessageLabel.setText("invalid entry");

}

public void checkGuess(int randomNumber)

{

maxtries++;

if(maxtries==10){

userMessageLabel.setText("You Lose!!");

guess.setEnabled(false);

enter.setEnabled(false);

}else if (userInput == randomNumber)

{

userMessageLabel.setText("Correct !");

}

else if (userInput > randomNumber)

{

userMessageLabel.setText("Too high");

}

else if (userInput < randomNumber)

{

userMessageLabel.setText("Too Low");

}

public static void main(String[] args)

{

Guess game = new Guess();

game.setVisible(true);

}

8 0

3 years ago

An ideal Rankine cycle operates with turbine inlet steam at 90 bar and 500°C, and a condenser at 40 °C. Calculate the efficiency

lilavasa [31]

Answer:

40.8%

Explanation:

A rankine cycle is a generation cycle using water as a working fluid, when heat enters the boiler the water undergoes a series of changes in state and energy until generating power through the turbine.

This cycle is composed of four main components, the boiler, the pump, the turbine and the condenser as shown in the attached image

To solve any problem regarding the rankine cycle, enthalpies in all states must be calculated using the thermodynamic tables and taking into account the following.

• The pressure of state 1 and 4 are equal

• The pressure of state 2 and 3 are equal

• State 1 is superheated steam

• State 2 is in saturation state

• State 3 is saturated liquid at the lowest pressure

• State 4 is equal to state 3 because the work of the pump is negligible.

Once all enthalpies are found, the following equations are used using the first law of thermodynamics

Wout = m (h1-h2)

Qin = m (h1-h4)

Win = m (h4-h3)

Qout = m (h2-h1)

The efficiency is calculated as the power obtained on the heat that enters

Efficiency = Wout / Qin

Efficiency = (h1-h2) / (h1-h4)

first we calculate the enthalpies in all states

h1=3386kJ/Kg

h2=2073kJ/Kg

h2=h3=167.5kJ/Kg

we use the efficiency ecuation

$Efficiency =\frac{(h1-h2) }{(h1-h4)} =\frac{3386-2073}{3386-167.5} =0.408=40.8%$

8 0

3 years ago