An Evolution of Hybrid Airship Vehicle (HAV) Envelope: Aerodynamics Analysis

Abstract

HAV has a potential application as the new means to carry Ultra Heavy Payload cargo since it combines the buoyancy capabilities of Lighter-than-Air (LTA), and the aerodynamics of lifting body of Heavier-than-Air (HTA) for speed. Due to its potential, American Institute of Aeronautics and Astronautics (AIAA) has issued a Request for Proposal (RFP) regarding the Hybrid Airship Vehicle (HAV) as cargo transportation with several requirements. AIAA RFP required an envelope that can produce 60% of the lift from buoyancy and 40% of lift from aerodynamic. To satisfy the RFP requirements, this paper analyzed 4 different designs using Computational Fluid Dynamic (CFD) software. Design 4 was chosen as the final design because it meets all the requirements. It was found that at 5° Angle of Attack (AOA), the envelope produce highest aerodynamic lift over drag (L/D) ratio of 3.79. At higher AOA, flow separation occurs at the envelope tail section jeopardizing the aerodynamic characteristic of Design 4 envelope. The lift and drag force graphs were plotted at this AOA and it was found that the HAV envelope is capable of performing the tasks in the RFP.