Date of Award


Level of Access Assigned by Author

Campus-Only Thesis

Degree Name

Master of Science (MS)


Mechanical Engineering


Mohsen Shahinpoor

Second Committee Member

Vincent Caccese

Third Committee Member

Xudong Zheng


The automotive industry has shown a great interest and dedication to build safer, easier to drive, cheaper and better performing vehicles. For example, the recently introduced Drive-by-Wire technology is going to replace the traditional mechanical control systems with electromechanical control systems in order to improve the existing automobiles. In other words, the traditional mechanical systems are being replaced by advanced electromechanical systems that are able to do the same tasks quicker, more reliably and more precisely.

MR fluid exhibits fast, strong, and reversible changes in its rheological properties when an external magnetic field is applied. Therefore, MR fluid holds a great potential in any application that requires an electromechanical interface. There have been a large number of research studies on developing MR brakes and clutches in many applications; but MR fluid has never been used in any transmission application to engage or disengage the gears.

The proposed design presents a new application for magnetorheological fluid as a viable alternative to the current conventional transmission systems. This system uses MR fluid rather than mechanical parts to shift the gear. The proposed design has some advantages over the current transmission systems, such as the ability to integrate with control features, smooth gear shift and lower system weight.

After introducing the basic design and its application, the design development process was started with making an analytical model of the proposed design and introducing some practical design considerations. A two-dimensional finite element model was created to simulate the steady-state magnetic flux flow within the MR fluid domain using COMSOL AC/DC Module. Then a 3D CAD model was generated and a prototype was manufactured to experimentally validate the FEA results for magnetic field over the MR fluid gap.

Finally the transferable torque for a sample design is predicted and the total weight of the designed system is compared to current transmission systems used in small passenger cars. Regarding the simulation results and weight comparison between the proposed design and current transmission systems, the propose design has some potential to be employed in small economic passenger cars.