Tsz Him Yeung

Date of Award


Access Type

Thesis - Open Access

Degree Name

Master of Science in Aerospace Engineering


Graduate Studies

Committee Chair

Dr. Richard P. Anderson

First Committee Member

Dr. Steven Daniel

Second Committee Member

Dr. Mark Ricklick


This thesis focuses on electric propulsion technology associated with serial hybrid power plants most commonly associated with urban air mobility vehicles. While closed form analytical solutions for parallel hybrid aviation cases have been determined, optimized serial hybrid power plants have not seen the same degree of fidelity. Presented here are the analytical relationships between several preliminary aircraft design objectives and the battery weight fraction. These design objectives include aircraft weight, range, operation cost, and carbon emissions. The relationships are based on a serial hybrid electric propulsion architecture from an energy standpoint, and can be applied to hybrid aircraft of different weights, aerodynamic designs, and propulsive efficiencies. Three hybrid electric propulsion design related variables are also defined in the process to help clarify novel specifications unique to hybrid propulsion systems. For all design objectives, the optimal battery weight fraction is found to be either zero or one in unconstrained cases. When a minimum range requirement is applied, non-integer weight fraction solutions can be found for minimizing cost and emissions.