Test The Limits

Keep the frost on the outside!

By Kamalesh Bhambare

October 28 2015

Global competition for market share is fierce in the automotive industry. Automotive manufacturers work hard to make their vehicles attractive to consumers to suit tastes and meet regulations in a variety of geographic regions. They also face the challenge to ensure their global products function well, regardless of diverse climate conditions and usage patterns that vary significantly from one region to another. Compliance with various government safety standards only adds to the complexity involved in the design and engineering of a world car.


A good example of such practical issues is what HVAC engineers have to do to design their climate control systems properly for a market with an extremely cold environment. When the ambient temperature is very low (around -20 degrees Celsius) and the vehicle is moving at a high speed, the moisture from the occupants’ breath can form “frost” on the interior sides of a vehicle’s windshield and side glasses. The frost impairs driver’s visibility, potentially leading to a serious safety issue. The vehicle’s HVAC system should be designed appropriately to be able to quickly remove the frost layer and prevent further formation.


Recent advances in climate control simulation methods, discussed in PowerFLOW's publication with SAE, make it possible to accurately predict the defrosting patterns. Design factors such as the defroster air flow speed and directions, blower performance, heater warm-up behavior, and the cabin ventilation characteristics can be evaluated digitally before the first prototype build. This simulation-driven process provides HVAC engineers with the opportunities for early-detection of potential issues.  Furthermore it offers great flexibility to optimize the HVAC components and sub-systems for the best performance with minimal costs


To see an animation of the SIMULIA PowerFLOW defrosting simulation, please click here