Drag and Power Impacts of Heat Removal in High-Speed Rotorcraft: Trending and Optimization

Current trends in the rotorcraft market favor aircraft with higher power electronic equipment, smaller, more efficient propulsion systems, and higher flight speeds. The power consumers are putting a greater tax on electrical systems, but also pushing already stressed thermal management systems. The first goal of this brief study aims to calculate and identify major trending of drag and power consumption imposed by equipment cooling on high-speed rotorcraft. Major contributors to these quantities include total heat load, equipment qualification temperature, flow passage sizing and inlet/exhaust orientation to free stream. During preliminary aircraft design, these factors are sometimes disregarded or deprioritized, as they may lead to weight increases, design challenges, and schedule changes. However, ignoring them tends to yield a cascade of other issues later in the design process, often in the way to airframe and electrical system, along with a decrement in overall aircraft performance. The second goal is to establish a very high-level system of preliminary assessment. Quantifying these impacts, as affected by their above noted underlying factors, in a simple, easily repeatable, preliminary design process, could potentially aid in illustrating potential issues and opportunities for optimization to a broader audience, earlier on in the design.