Characterization of Inlet Contamination Potential - Teresa Campos - The cabin exhaust valve is located just aft of the nose on the right fuselage. The cabin volume of 2400 cu ft undergoes complete turnover of fresh air in 2.8 minutes, implying about 70kL/min flow rate exiting the cabin. To check the potential for sampling boundary layer air with the HIMIL, it was proposed to release a pulse of high concentration of CO2 at the cabin exhaust vent and alternately sample from the HIMIL and boundary layer ports. This exercise was conducted during speed runs and level flight legs. Flow was split to look for cabin CN using this inlet. In this figure, the BL depth was ~4.0" for both the fastest and slowest flight speeds. Note on this semi-log plot that the profile of dynamic pressures is approximately a straight line within the BL. qcR, qcF are dynamic pressures at the Radome and Fuselage pitot tube.

Characterization of Inlet Contamination Potential Due to time and instrument performance limitations, only one aperture location was tested for CO2 contamination sampling during Progressive Science: FS 498R. Data have not been fully analyzed. Preliminary results imply that during straight and level flight, boundary layer air is not sampled even at the HIMIL distance from the fuselage. However, enhancement of CO2 above background levels is observed at even small changes in aircraft attack angle. In this figure, the BL depth was ~4.0" for both the fastest and slowest flight speeds. Note on this semi-log plot that the profile of dynamic pressures is approximately a straight line within the BL. qcR, qcF are dynamic pressures at the Radome and Fuselage pitot tube.