van der Maas J, Schaelin A
Year:
1995
Bibliographic info:
16th AIVC Conference "Implementing the results of ventilation research", Palm Springs, USA, 18-22 September 1995

In line maintenance hangars, air planes stay about 2 hours, usually at night-time. The coolingdown of the inside air during the opening time of the hangar gates (up to 5 times per night, lasting 15 to 30 minutes each) has a considerable impact on the comfort conditions for the workers, and on the energy required for reheating. The time-dependent air flow rates and associated heat loss rates during the door opening and closing cycles is assessed by simple transient thermal models and CFD (Computational Fluid Dynamics) calculations. The results obtained by these models agree well with the experimental data of the transient temperature response during the opening and closing of the door of a real full-scale hangar. The effect of using huge air curtains (up to a height of 20 m, a width of 80 m, and moving air volumes at rates of 400 m³/s) to prevent heat loss was studied numerically by CFD in two- and three-dimensional models for time-dependent conditions. The study covers also transient effects when an aircraft is actually crossing the air curtain, and shows the feasibility of assessing the energy saving potential of such air curtains using CFD.