3003 W CASINO RD PAINT HANGAR BOUNDARIES 2023-07-20

Geminus Boeing Project Contract No.EVE-16-2929 L'w Technology Development CEI Project No. 160731 Alternative ventilation scenarios (e.g., 75% Ventilation Paint Mode) were based from the values used in Nominal Paint Mode. Note that the ventilation specifications are different between the current 45-04 and the to-be-modified 45-04 system. Ventilation values for-the modified 45-04 were generated by Boeing on a per-zone with the per-zone airflow further distributed on an individual supply basis [7]. The following assumptions were made for the ventilation air supply and exhaust model in the CFD simulations • Current (un-modified) 45-04 air flows and exhaust distributions are from data taken from [5] and are maintained during Case 1 simulations and represent a 100% airflow case. • The modified 45-04 100% air flow and variations of the supply and exhaust distributions for different Case 2 and Case 3 scenarios are per Boeing specifications [7]. • A "Ventilation Fail" mode CFD analysis was not performed as was deemed un- necessary based on 45-03 simulation results [2]. • Vast majority of the building air leakage is from the hangar door seals The above assumptions impose the following limitations on the model: • Significant deviations from the desired/design air supply and exhaust mass flow distributions or flow rates beyond those specified in the Scenarios modeled will likely have a significant effect on the % of LEL concentrations, both locally and globally depending on the type and degree of airflow deviation. 2.2.3 Volatiles Release Model The 45-04 CFD analysis volatiles release calculations & paint gun models are identical to those used in the preceding 45-03 CFD analysis [2] and are repeated here for completeness with minor modifications. 2.2.3.1 Painting Scenario & Volatiles Content For Case 1, Scenario 2, the CFD paint model was based on clear coat 3002G0002 described in [8]. The clear coat was chosen based on the large overspray "cloud" it creates, which is a function of droplet diameter and overall liquid flow rates. Table 1 shows the ingredients of the paint and the mass flow rates used in the CFD model. References [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], and [19] show properties of the clear coat ingredients. For Cases 2 and 3, it was decided by Boeing to use the Run 3 sensitivity spray gun condition instead of the clear coat baseline condition. The following assumptions were made regarding the paint model: • For the clear coat, 40% of the volatiles leaving the spray gun end up in the overspray cloud (i.e., a 60% clear coat transfer efficiency). This is a conservative assumption because the least efficient spray guns used in the hangar have transfer efficiencies of—70% and other models have 80% transfer efficiency. [20] • For Run 3 spray gun conditions, 70% transfer efficiency was assumed. 12