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LitGeminus Boeing Project Contract No.EVE-16-2929 <br /> Technology Development CEI Project No. 160731 <br /> 2.3 Summary Of CFD Model Inputs <br /> 2.3.1 45-04 Ventilation Upgrade <br /> The ventilation consists of supply diffusers in the hangar ceiling and exhaust grates in the <br /> floor. The supply diffusers are divided into 16 zones. The diffusers are also assigned a <br /> designation that determines its size and air flow rates for Ventilation Paint Mode. <br /> The total exhaust flow rate is slightly higher than the supply flow rate which creates a <br /> negative pressure differential between the hangar and the exterior. To accommodate this in <br /> CFD, gaps between the hangar doors were included in the model. These gaps use a pressure <br /> boundary condition which allows air flow in to make up the difference between the supply and <br /> exhaust flow rates. <br /> 2.3.2 Hangar Shell <br /> The hangar building shell was generated by Geminus based on Boeing-supplied mechanical <br /> drawings of the 45-04. The shell included floor patches for each exhaust and ceiling features for <br /> primary and secondary air supplies. These floor/ceiling features were changed from the 45-04 <br /> original design to the new design as illustrated in Figure 5. For Case 1 a simple hangar door <br /> model was developed with 2" wide vertical air leakage paths allowed at the door centerline and <br /> at each door overlap location. The recesses or door pockets were not modeled. Initial Case 2 <br /> simulations showed that additional door leakages were required, thus a more sophisticated door <br /> geometry was developed that included additional leakage paths at all the door overlaps and the <br /> door pockets. <br /> Figure 5 shows the plan view of the hangar 3D CAD model used in CFD Case 1 including <br /> supply and exhaust locations. Figure 6 shows the plan view of the hangar 3D CAD model used <br /> in CFD Case 2 and Case 3 including ceiling air supply and floor exhaust locations. A full 3D <br /> CAD model of the hangar shell (volume) was created. <br /> 0. o <br /> 0 0 0 0 ❑ <br /> • c • o 0 0 <br /> a• <br /> •:1 e ° 0 0 0 BB ®❑ <br /> �I.• 00 0 0 o a <br /> • oor�c�c_v U O P o00 6 6 m m®®corm=mormcrso mm, <br /> 0 0 0 0 o a ❑o a <br /> Q P(� nl0000leo0 �] 17 0� O 8•'0 <br /> Om <br /> ') Il� 0 8 8 oQa <br /> c� 8 ....a <br /> e 11 I B : EP®o <br /> a o 0 <br /> ❑ ❑ <br /> o • <br /> Figure 5: Hangar 45-04 Shell For CFD Case 1 Simulations (Original Hangar <br /> Geometry). Exhaust Layout On Left, Supply Layout On Right. Note that the <br /> outboard engine primary and secondary air supplies were turned off. <br /> 14 <br /> 1 <br />