Simulated Drag Study of Fuel Tank Configurations for Liquid Hydrogen-Powered Commercial Aircraft

The airline industry faces a crisis in the future as consumer demand is increasing, but the environmental effects and depleting resources of kerosene mean that growth is unsustainable. Hydrogen is touted as the leading candidate to replace kerosene, but it needs significant technological and economical endeavors. In such a scenario, cryogenic liquid hydrogen (LH₂) is predicted to be the most feasible method of using hydrogen. The major challenge of LH₂ as an aircraft fuel is that it requires approximately four times the storage volume of kerosene—due to its lower density. Thus the design of cryogenic storage tanks to handle larger quantities of fuel is becoming increasingly important. But the increase in drag associated with larger storage tanks causes an increase in fuel consumption. Hence, this paper aims to evaluate the aerodynamic performance of different storage configurations and aid in the selection of an economic and efficient storage system. Using an Airbus A321 replica as the base model, we sized internal and external tanks to meet the mission fuel requirements and modelled the composite aircraft on SolidWorks^®. Then we carried out flow simulation in ANSYS Fluent^® to compute the lift and drag values of each storage configuration. For external tanks, we observed that a novel airfoil cross-section tank had the lowest drag value; it performed better than the capped cylinder tanks. Also external tanks kept below the wing lead to minimal disruption of the airflow. Among the internal configurations, we found that increasing the fuselage length is the most aerodynamically efficient way to store the fuel.