This Java program calculates fluid flow rate and velocity in a pipe given input parameters like diameter, length, viscosity, density, head loss, and roughness. It creates a GUI with labels and text fields to input these parameters. Buttons are used to calculate the flow rate and velocity, displaying the results, or to clear the input fields. Calculations are performed in a loop that iterates to solve for the friction factor using the Colebrook equation.

1.
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.border.Border;
public class FlowRateFinder extends JFrame { // opens main class.
// creates all the Panels needed in the program
private JPanel labelPanel1;
private JPanel labelPanel2;
private JPanel calcPanel;
private JPanel buttonPanel;
// creates all the labels needed in the program
private JLabel dia;
private JLabel dens;
private JLabel len;
private JLabel visc;
private JLabel grav;
private JLabel hF;
private JLabel flowRateTxt;
private JLabel calculatedValue;
private JLabel velocityTxt;
private JLabel velocityCalc;
private JLabel fFactor;
private JLabel roughValue;
// creates all the buttons in the program
private JButton calcBtn;
private JButton clearBtn;
// creates all the text fields in the program
private JTextField diameter;

2. private JTextField density;
private JTextField length;
private JTextField viscosity;
private JTextField gravity;
private JTextField headLoss;
private JTextField fFactorTxt;
private JTextField roughValueTxt;
private Border blackline = BorderFactory.createLineBorder(Color.black);
public FlowRateFinder() { // constructor for the Object
// sets the GUI parameters.
super("Flow Rate Finder");
setDefaultCloseOperation(EXIT_ON_CLOSE);
setBounds(10, 10, 700, 400);
setLayout(new GridLayout(4,1));
// creates the panels and their overall layouts.
labelPanel1 = new JPanel(new GridLayout(3,2));
labelPanel2 = new JPanel(new GridLayout(3,2));
calcPanel = new JPanel(new GridLayout(2, 2));
// block of variable initializers for the variable diameter
dia = new JLabel("diameter (m)");
dia.setHorizontalAlignment(JLabel.CENTER);
dia.setBorder(blackline);
diameter = new JTextField("", 10);
diameter.setHorizontalAlignment(JTextField.CENTER);
diameter.setBorder(blackline);
// allocates info to the variable density.
dens = new JLabel("density (kg/m^3)");
dens.setHorizontalAlignment(JLabel.CENTER);
dens.setBorder(blackline);
density = new JTextField("", 10);
density.setHorizontalAlignment(JTextField.CENTER);
density.setBorder(blackline);
// allocates info to the variable length.
len = new JLabel("length (m)");

3. len.setHorizontalAlignment(JLabel.CENTER);
len.setBorder(blackline);
length = new JTextField("", 10);
length.setHorizontalAlignment(JTextField.CENTER);
length.setBorder(blackline);
// allocates info to the variable viscosity.
visc = new JLabel("viscosity (kg/ms)");
visc.setHorizontalAlignment(JLabel.CENTER);
visc.setBorder(blackline);
viscosity = new JTextField("", 10);
viscosity.setHorizontalAlignment(JTextField.CENTER);
viscosity.setBorder(blackline);
// allocates info to the variable gravity.
grav = new JLabel("gravity (N/kg)");
grav.setHorizontalAlignment(JLabel.CENTER);
grav.setBorder(blackline);
gravity = new JTextField("", 10);
gravity.setHorizontalAlignment(JTextField.CENTER);
gravity.setBorder(blackline);
// allocates info to the variable headloss
hF = new JLabel("head­loss (ft)");
hF.setHorizontalAlignment(JLabel.CENTER);
hF.setBorder(blackline);
headLoss = new JTextField("", 10);
headLoss.setHorizontalAlignment(JTextField.CENTER);
headLoss.setBorder(blackline);
// allocates info to the calculation field.
flowRateTxt = new JLabel("Your flow rate is: (m^3/s)");
flowRateTxt.setHorizontalAlignment(JLabel.CENTER);
flowRateTxt.setBorder(blackline);
calculatedValue = new JLabel("");
calculatedValue.setHorizontalAlignment(JLabel.CENTER);
calculatedValue.setBorder(blackline);
velocityTxt = new JLabel("Your average velocity is: (m/s) ");
velocityTxt.setHorizontalAlignment(JLabel.CENTER);
velocityTxt.setBorder(blackline);
velocityCalc = new JLabel("");
velocityCalc.setHorizontalAlignment(JLabel.CENTER);
velocityCalc.setBorder(blackline);

4.
// adds information to the calculation panel.
calcPanel.add(flowRateTxt);
calcPanel.add(calculatedValue);
calcPanel.add(velocityTxt);
calcPanel.add(velocityCalc);
// adds information to the initial guess and the roughness level.
fFactor = new JLabel("friction factor: ");
fFactor.setHorizontalAlignment(JLabel.CENTER);
fFactor.setBorder(blackline);
fFactorTxt = new JTextField("", 10);
fFactorTxt.setHorizontalAlignment(JTextField.CENTER);
fFactorTxt.setBorder(blackline);
roughValue = new JLabel("roughness E/D: ");
roughValue.setHorizontalAlignment(JLabel.CENTER);
roughValue.setBorder(blackline);
roughValueTxt = new JTextField("", 10);
roughValueTxt.setHorizontalAlignment(JTextField.CENTER);
roughValueTxt.setBorder(blackline);
// adds information to the first label panel.
labelPanel1.setBackground(Color.cyan);
labelPanel1.add(dia);
labelPanel1.add(diameter);
labelPanel1.add(dens);
labelPanel1.add(density);
labelPanel1.add(len);
labelPanel1.add(length);
// adds information to the second label panel
labelPanel2.setBackground(Color.cyan);
labelPanel2.add(visc);
labelPanel2.add(viscosity);
labelPanel2.add(grav);
labelPanel2.add(gravity);
labelPanel2.add(hF);
labelPanel2.add(headLoss);
// adds information to the buttons and button panel
calcBtn = new JButton("Calculate!");
clearBtn = new JButton("Clear!");

5. buttonPanel = new JPanel(new GridLayout( 3, 2));
buttonPanel.setBackground(Color.cyan);
buttonPanel.add(fFactor);
buttonPanel.add(fFactorTxt);
buttonPanel.add(roughValue);
buttonPanel.add(roughValueTxt);
buttonPanel.add(calcBtn);
buttonPanel.add(clearBtn);
// adds all the panels to the main frame.
add(labelPanel1);
add(labelPanel2);
add(buttonPanel);
add(calcPanel);
// allows for the buttons to actually initiate calculations.
ButtonListener btnListn = new ButtonListener();
calcBtn.addActionListener(btnListn);
clearBtn.addActionListener(btnListn);
// allows user to see the GUI
setVisible(true);
}
// action listener that waits for a button to be pressed and performs actions
// based on the click.
public class ButtonListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
// does calculations if the calculation button is pressed.
if(e.getSource() == calcBtn) {
try{
// takes all the strings input by the user and converts them to
doubles.
double den = Double.parseDouble(density.getText());
double l = Double.parseDouble(length.getText());
double hL = Double.parseDouble(headLoss.getText());
double g = Double.parseDouble(gravity.getText());
double dia = Double.parseDouble(diameter.getText());
double mu = Double.parseDouble(viscosity.getText());

6.
//initializes all other variables needed in the calculation.
double frictionFactor = Double.parseDouble(fFactorTxt.getText());
double ReynoldNum;
double kinVisc = mu/den;
double tempFF = 0;
double roughFact =
Double.parseDouble(roughValueTxt.getText());
double v;
double area = (Math.PI * Math.pow(dia, 2)) / 4;
do { // do­while loop that will do the first calculation then initiates a
while loop
// does the calculation
tempFF = frictionFactor;
v = Math.sqrt((2 * hL * dia * g)/(frictionFactor * l));
ReynoldNum = ((v * dia)/ kinVisc);
frictionFactor = Math.pow(­1.52 *
Math.log10((Math.pow((roughFact/7.21), 1.042) + Math.pow((2.731/ReynoldNum), 0.9152))),
­2.169);
} while((frictionFactor ­ tempFF) > .0001);
double FlowRate = area * v;
// this part takes the calculations and displays them "nicely"
calculatedValue.setText(Double.toString(FlowRate));
calculatedValue.setBackground(Color.green);
calculatedValue.setOpaque(true);
velocityCalc.setText(Double.toString(v));
velocityCalc.setBackground(Color.green);
velocityCalc.setOpaque(true);
} catch (NumberFormatException z) {
// catches anything that is not a number input.
calculatedValue.setText("Oops! You entered illegal
characters, try again!");
}
}

7. // clears the GUI if the clear button is pressed.
if(e.getSource() == clearBtn) {
// sets everything back to the default.
diameter.setText("");
density.setText("");
viscosity.setText("");
headLoss.setText("");
gravity.setText("");
length.setText("");
fFactorTxt.setText("");
roughValueTxt.setText("");
calculatedValue.setText("");
calculatedValue.setOpaque(false);
velocityCalc.setText("");
velocityCalc.setOpaque(false);
}
}
}
public static void main(String[] args) {
FlowRateFinder test = new FlowRateFinder();
}
} // closes main class.