Project Report on Fuel Efficiency in All Wheel Drive (AWD) System

 Abstract.
      The main tasks of this thesis work were to investigate the size of the power losses in
different parts on the propeller shaft, to design a computer program that calculates
coordinates and angles on a propeller shaft and to investigate the possibilities to put
together a simplified formula that calculates the natural frequencies on a propeller
shaft.
The main parts of this report are a compilation of the theory about AWD and mostly
about the parts on the propeller shaft, and also a description of the developed
computer program called Propeller Shaft Calculator. This report doesn’t concern
power losses in the different joints because there were no such general equations to be
found. The most common way to calculate the power losses inside a joint is to do tests
were the power loss is measured at different angles, torque and speed and then use
that data to put together an approximated equation.
Most of the work on this project has been on theory studies and on programming.
The main result of the project is the program Propeller Shaft Calculator. Propeller
Shaft Calculator is a program that is designed in Microsoft Excel. All the menus are
programmed in the visual basic editor in Excel. The program is supposed to be used
as a help while designing new propeller shafts.
Propeller Shaft Calculator can calculate all the coordinates, lengths, angles and
directions on a propeller shaft. It also calculates natural frequencies, plunge, estimated
power loss on the second shaft and angles in the joints. In the program you can choose
to do calculations on four different configurations of propeller shafts but can quite
easy upgrade the program with more choices.
Basically the program works like this:
First you choose the right propeller shaft in the main menu. Then you fill out the indata
sheet with coordinates, lengths, material data and so on. As you type in the input
data the output data will appear in the out-data sheet next to the in-data. Every
propeller shaft has also a calculations sheet were more detailed calculations can be
found.
The program also has a built in help function and a warning function that lights a
warning sign next to the values if they are outside the limit.


Introduction
           There is always an interest in lowering the fuel consumption within the Automotive
industry because of the competition when the fuel price increases. New cars are
supposed to consume less fuel all the time. The requirements on the different systems
are constantly increasing. All this is carefully followed up in the development projects
off new car models.
In this report a number of components in the AWD-system will be studied to se if
there are any possible improvement potentials. The chosen components that will be
studied are the propeller shaft, the joints and the bearings. The parts will be studied to
se if they could be designed to be me more effective or if there are any better options
on the market that are more energy saving.
To make the design of a new propeller shaft easier and more time saving a new
computer program has been developed together with engineers at Saab Automobile.
The program is made in Microsoft Excel and can calculate lengths, angles, natural
frequencies, plunge and power losses on the propeller shaft.
This work has been made as a thesis work for a bachelor degree and the report
together with the computer program is the result.


Download Project on Fuel Efficiency in All Wheel Drive (AWD) System