Engine Testing Calculation Sheet

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Subject: E03 114 Introduction to Maritime Engineering Industry - 2006Last modified in March 2006 by Hung Nguyen. Copyright 2006 AMC

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Tutorial 6a Using MS Excel

Multiple Sheets

Introduction

Multiple worksheets provide a useful way of organising data into logical groupings. For this

exercise we shall be using four worksheets to keep information about the experimental result of an

engine at four different test speeds.

Exercise 1

Turn on and log in to the computer.

Click on Microsoft Excel in the menu.

Centre align cells A3:G8.

Format C4:E8 to have two decimal places, F4:F8 to have three decimal places and G4:G8 to have

one decimal place.

In cells A3:G3, type in the following headings: Speed, Torque, Fuel Time, Brake Power,

bmep, bsfc, and Thermal Efficiency.

Enter in the value 1800 in cell A4 and copy down to cell A8.

In cells B4:B8 enter the following values: 60, 130, 180, 200, 210.

In cells C4:C8 enter the following values: 75.25, 45.96, 36.5, 32.85, 31.09.

Click onto the number 4 button in the left hand side of the spreadsheet. All the cells in row number

4 should be highlighted.

Select Insert Rows to insert a new blank set of cells in row 4. In row 4, enter the appropriate

units below for each of the headings:

Speed rpm

Torque NmFuel Time sec

Brake Power kW

BMEP bar

bsfc kg/kWh

Thermal Efficiency %

The screen should look like


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Now, enter some formulas:

The formula for brake power (bp) as follows

bp(W) = torque (Nm) by speed (rad/s)

In cell D5 enter the formula as follow: =(2*PI()*(A5/60)*B5)/1000

Note that pie ( ) is a build in a constant with the designation PI().

Copy the formula in cells D6:D9.

Calculate BMEP (brake mean effective pressure) in units of kPa by the following formula:

bmep (kPa) = 2bp (cylinder volume rev/s)

In cell E5, enter the formula: =(2*D5)/(0.000864*A5/60)/100

Note that the final divide by 100 converts the result from kPa into bar.

Copy the formula into cells E6:E9.


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Calculate bsfc (brake specific fuel consumption) in units of kg per kilowatt hour by the following

formula:

bsfc (kg/kWh) = fuel mass flow rate (kg/h) bp (kW)

In cell F5, enter the formula: =3600*825*(0.0001/C5)/D5

Copy the formula into cells F6:F9.

Calculate the thermal efficiency by the following formula:

Thermal efficiency (%) = [bp (kW) (calorific value of fuel (kJ/kg) fuel mass flow (kg/s))]100

In cell G5, enter the formula: =D5/(43000*(825*0.0001/C5))*100

Copy into cells G6:G9.

The screen should look like this


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Insert two rows and type in the title Diesel Engine Test in cell C2, centre the text and set the font

size to 16 in Times New Roman.


Save the file as Diesel Engine Tests.xls

Task

Create a grid around cells A5:G11. Hint: look up Format Cells Border.


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Exercise 2



Open the file Diesel Engine Tests.xls (you created in Exercise 1).

Workbooks come with three default worksheets. For this tutorial we need four and so our first task

is to add an additional work sheet into our workbook.

Select the menu Insert and Worksheet to insert a fourth work sheet.

Now to rename the Worksheet tabs into something more suitable than the defaults Sheet 1 Sheet

4 (if there is not Sheet4, point the mouse in Sheet3, right-click and insert Sheet4). Place the mouse

on the Sheet 1 tab and double click the left mouse button. The name will be displayed in reverse

video text.

Type in 1800 rev-min.

Rename Sheets 2-4 as 1500 rev-min, 1200 rev-min and 1000 rev-min, in the same way.


Copy the cells A1:G11 from the 1800 rev-min worksheet and paste into 1500 rev-min worksheet.

Adjust the width of columns A-G.

Change the value in cell A7 to 1500 and copy down to cell A11.

Change the values in cells B7:B11 to 60, 130, 180, 200, 220.

Change values in cells C7:C11 to 101.19, 61, 46.1, 41.22, 39.31.



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Note that the values of Brake Power, BMEP, bsfc and Thermal Efficiency are automatically

calculated because you have copied the formulas from the 1800 rev-min work sheet.





Change values in cells C7:C11 to 129.63, 75.47, 58.03, 52.59, 45.56.



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Change values in cells C7:C11 to 151.94, 89.44, 66.16, 59.19, 52.



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Save all changes.

Task

You can make multiple copies of a worksheet as follows.

Place the mouse cursor over the 1800 rev-min tab and hold down the left mouse button. Hole the

Ctrl button down and at the same time, move the cursor over to another tab. Release the mouse

button first and then the Ctrl button. A copy will be created of the 1800 rev-min worksheet.

An alternative way of creating the 1500, 1200 and 1000 rev-min worksheets would be to make three

copies of the 1800 rev-min worksheet. Rename them as 1500 rev-min, 1200 rev-min and 1000 rev-

min. Then enter the data for Speed, Torque and Fuel Time as appropriate.


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Tutorial 6b Using MS Excel

Multiple Series Charts

Introduction

It is now time to chart some of the data. It is easy using the Chart Wizard to create multiple data

series against a single column but in this case we want to plot four pairs of data on the one graph.

Although each data pair has the same X axis of BMEP, the actual values are not necessarily the

same. This exercise shows how to create a single chart that shows the variation of bsfc with BMEP

at various engine speeds.

Exercise 6b.1



Open the file Diesel Engine Tests.xls from the previous tutorial, Exercise 6b.2.

Select the cells E7 to F11 as shown below.

Select the menu item Insert and Charts, or click on the Charts button in the standard

toolbar.

Select the Scatter with data points connected by smoothed lines option and then click the Next

button.


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Select the Series tab in the Step 2 dialog box.



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In the name textbox, insert the name 1800.

Copy (Ctrl+C) the entry in the X Values text box.

Press the Add button at the bottom of the Series list box.

Name the series 1500.

Paste (Ctrl+V) the values copied from the 1800 X Values into the X Values for the 1500 series.

Create two more series, 1200 and 1000 and also paste in the 1800 X Values.

Edit the 1800 in each of the X Values to reflect the appropriate engine speed, i.e. 1500, 1200 and

1000.

Hint: Place cursor to the right of the 8. Use Backspace key to delete and type in the require value (5,

2, or 0).

The screen should be similar to the following


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Repeat the process for the Y Values. Copy the Y Values for the 1800 series and paste it into the Y

Values for all the other series (1500, 1200, 1000).

Edit the 1800 in each of the Y Values to reflect the appropriate engine speed, i.e. 1500, 1200 and

1000.



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Click the Next button to obtain the Step 3 dialog box.

Type in Diesel Engine Test for the Chart title.

Type in bmep (bar) for the X axis.

Type in bsfc (kg/kWh) for the Y axis.

The screen should be similar to the following


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Click the Next button to obtain the Step 4 dialog box.

Select the As new sheet.

Click the Finish button.



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The default name Chart 1 can be change if required.

Save all the changes.

Tasks

Create a chart of Torque against Thermal Efficiency for the four engine speeds. Try and create a

3D-surface chart (3D-Surface). Shows trends in values across two dimensions in a continuous line

of bmep against bsfc at four engine speeds.

Submission: Send all your completed Excel files to Hung Nguyen [email protected] ONE

TIME. Do not forget to include your name and IDin your email or Excel files.

Engine Testing Calculation Sheet

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