Simulating ice

摘要

Researchers are relying more on computational analysis to see how aircraft designs and ice-protection systems will react in icing conditions. Every winter, passengers, airlines, and the FAA are forced to deal with disruptions, delays, and danger due to icing. In fact, since 1993 icing has brought down 135 aircraft and killed 171 people, according to the National Transportation Safety Board. Icing affects aircraft by adding weight and, more importantly, by altering the shape, and hence the aerodynamics, of the wings. Long before pilots face the hazards of flying through icing conditions, aircraft manufacturers evaluate how icing affects the performance of the planes they design and build. They have several ways to do this. The most direct and costly approach is to fly the aircraft through actual icing conditions. This lets a manufacturer assess how ice accretion or buildup affects the vehicle's aerodynamics and how well its ice-protection system works. Alternatives to flight testing include wind-tunnel testing and computational simulation. Increasingly, manufacturers use a combination of all three to evaluate how aircraft behave in icing conditions. The method that has seen the most advances in recent years is computer simulation. Faster computers, better algorithms, and advanced software let engineers and scientists more accurately model and understand ice buildup, evaluate changes in aircraft performance, and analyze ice-protection systems.