en سوخت های جایگزین Modern Powertrain (hybrid, electric, CNG, bio, ...) پژوهشي Research <span style="font-size:10.0pt"><span style="line-height:115%"><span new="" roman="" style="font-family:" times=""><span style="color:black">In the automotive industry, reducing torsional vibrations caused by combustion irregularities and internal inertial forces is essential for improving powertrain quality, NVH (Noise, Vibration, and Harshness), and component durability. This study introduces and analyzes an innovative dual mass flywheel (DMF) with polymer bearings, aimed at enhancing torsional damping and ensuring smoother torque transmission in six-cylinder gasoline engines. The DMF consists of two masses, low-stiffness springs, and polymer bearings, all thoroughly modeled. Both linear and nonlinear dynamic analyses were performed, incorporating factors such as centrifugal force, nonlinear friction, and viscous damping. Component parameters were obtained via modal tests and experimental measurements. To validate the model, cylinder pressure and torque data were collected using sensors and a dynamometer, then compared with simulation results. Results reveal that employing the DMF reduces output torque fluctuations by up to 89.9% and significantly increases torsional vibration damping without a notable weight increase. Compared with a single-mass flywheel of equal inertia, the DMF decreased torque fluctuation amplitude by 46%, 41%, and 38% at 2250, 3000, and 3750 rpm, respectively. Achieving similar damping with a single-mass flywheel would require over an 80% mass increase. The nonlinear model provided a close match to experimental data, with simulation error below 5%. Overall, this integrated approach demonstrates that the dual mass flywheel with polymer bearings improves dynamic engine performance, NVH, and powertrain durability. These findings support the development of lighter, more advanced powertrain systems for next-generation vehicles.</span></span></span></span> Dual-mass flywheel, Power transmission system, torque fluctuations, linear modeling, nonlinear modeling, dynamometer testing, 4906 4921 http://ase.iust.ac.ir/browse.php?a_code=A-10-860-1&slc_lang=en&sid=1 Seyed Ali Mousavi amousavi@ihu.ac.ir 180031947532846005227 180031947532846005227 No Ph.D. , Mechanical Engineering Department ,Imam Hossein University, Tehran, Iran Saeed Mahjoub Moghadas smahjoubmoghadas@ihu.ac.ir 180031947532846005228 180031947532846005228 Yes Associate professor, Mechanical Engineering Department ,Imam Hossein University, Tehran, Iran Hosein Mansouri hmansouri@ihu.ac.ir 180031947532846005229 180031947532846005229 No Assistant professor, Mechanical Engineering Department ,Imam Hossein University, Tehran, Iran