It can be concluded that the air-gap plays a very important role in the performance
of the SLIM. The air-gap needs to be as small as possible to have a better thrust and
efficiency. Another crucial design parameter is the thickness of rotor outer layer which is
aluminum. As the thickness of the aluminum sheet is increased thrust also increases along
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with the length of magnetic air-gap which is undesirable. Hence, care should be taken in
choosing the best value for aluminum thickness which yields maximum thrust at a
reasonable efficiency. The number of poles in the stator was the last parameter that was
varied to observe the SLIM performance curves. By increasing the number of poles, the
end effects are reduced, which is good for the SLIM performance. At the same time
thrust is increased but at the expense of efficiency. Hence, there is a trade off between the
thrust and the efficiency with increasing number of poles.
So, from the parametric evaluation which in performed in Chapter 5, it can be
concluded that the input parameters like the length of physical air-gap, the thickness of
aluminum sheet and the number of poles play a vital role in the performance parameters,
thrust and efficiency. Therefore, care should be taken in choosing these parameters.
Based on our target values of rotor velocity and thrust, these parameters should be chosen
which gives the best possible thrust closest to the target value at a decent value of
efficiency.
Finally, the design parameters of SLIM and a similar TLIM are compared in table
5-4. It can be seen that by introducing an extra iterative loop in the design algorithm, a
better performance parameters can be obtained compared to TLIM [29]. Hence it can be
concluded that the design algorithm was modified appropriately to get better results for
the design of the SLIM having the same design parameters as that of a TLIM shown in
[29]. Also the final thrust from this design is very close to the target thrust which is
desirable.