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

Gemnus Boeing Project Contract No.EVE-16-2929 Technologyi Development CEI Project No. 160731 Figure 26 shows the comparison of the fuselage velocities along the length of the fuselage at the "waterline just under the windows" from the nose to the beginning of the empennage. As with the previous measurement set it was assumed that the fuselage measurements match the layout for 45-04, shown in Figure 21. As with the crown velocity measurements the fuselage measurements show a significant variation along the length of the fuselage as does the CFD data. The variation in the CFD data is due to the low velocity zones convecting down the aircraft sides from the crown as well as complex nearly stagnant flow over the wing root area. Figure 26 shows large velocity magnitude discrepancies between the CFD and data with the data — see discussion below. Comparisons of the vertical velocity component around the wing and engine cowl are shown in Figure 27 and Figure 28. The positions around the periphery of the wing and engine cowl were approximately located according to the designations illustrated in Figure 20. It should be noted that the VelGrid instrument is rated for >50FPM velocities and cannot measure reversed flow (negative) velocities - as such it is anticipated that velocities below 50FPM would have a large measurement error and any recorded negative velocities are actually zero. In general, the CFD does a very good job matching to the measured data, particularly for the wing and horizontal stabilizer peripheries. Again is should be noted that the measured points have an approximate location and are an average over a —12" square surface. Figure 29 shows the comparison of the vertical velocities around the horizontal stabilizer. As with the previous measurement set it was assumed that the horizontal stabilizer measurements match the layout for 45-04, shown in Figure 20. As in the case with the fuselage, there are large discrepancies between the CFD and data around the horizontal stabilizer. The comparison between the crown and fuselage vertical velocity measurements, the vertical velocities around the wing, horizontal stabilizer, and engine with those calculated with the CFD model shows that: • To within the measurement error/scatter, the CFD model is doing very well replicating the airflow velocity near the crown where a majority of the painting (and flammable volatiles being emitted) will occur (the other location being the engine cowl). This is particularly important as the flow around the spray gun/aircraft determines the initial dilution and path of the overspray from the paint gun. • The measured vertical velocities around the wing are also very well replicated by the CFD to within the measurement scatter and accuracy of the measurements taken However, as previously noted, there are large discrepancies between measurement and the CFD data next to the fuselage and horizontal stabilizers. GTD investigated the air velocity measurements, including having discussions with Neurdorfer and the equipment manufacturer (Shortridge Instruments). GTD also audited the CFD solution by refining the mesh around measurement locations and looking at the sensitivity of the reported CFD velocity data with distance from the fuselage and horizontal stabilizer. Refining the grid and varying the distances did not significantly affect the reported CFD velocity data. Based on its investigation and audit, GTD concluded that the measurements were not correct for the following reasons: 36