Jeffrey S. Allen

Jeffrey S. Allen


  • John F. and Joan M. Calder Endowed Professor in Mechanical Engineering-Engineering Mechanics
  • Associate Chair and Director of Undergraduate Studies, Mechanical Engineering-Engineering Mechanics
  • PhD, Mechanical & Aerospace Engineering, University of Dayton
  • MS, Mechanical & Aerospace Engineering, University of Dayton
  • BSE, Mechanical & Aerospace Engineering, University of Dayton


Dr. Allen is an experimentalist interested in the study of two-phase flow in capillary systems; such as found in the gas flow channels and diffusion media of PEM fuel cells. The behavior of liquid water in the internal passages of Proton Exchange Membrane (PEM) fuel cells, a class of low temperature fuel cells, presents a serious challenge to the development of reliable and efficient power units. The factors which influence capillary flow are well established (contact angle, geometry and surface tension), but the behavior of gas-liquid flows subject to capillary phenomena in the complex, manifolding passages of PEM fuel cells is not fully understood. Other active research involves investigations of the stability of evaporating and condensing liquid films, microfluidic systems such as lab-on-a-chip, microfluidic diagnostic development, design and optimization of micro-fuel reformers, and low-gravity fluid dynamics.

Links of Interest

Areas of Expertise

  • Capillary Flow
  • Interfacial Transport Phenomena
  • Fuel Cells
  • Phase-Change Heat Transfer
  • Microgravity Fluid Physics

Research Interests

  • Stability of evaporating and condensing liquid films
  • Capillary-Scale Gas-Liquid Flow
  • Near-Field Optical Diagnostics
  • Thermal and Mass Transport in Porous Media and Fuel Cells
  • Low-gravity fluid dynamics
  • Weak Atmospheric Shock Waves