Search Results

Temperature Sensitive Paint (TSP) technology coupled with the Reynolds number capability of modern wind tunnel test facilities produces data required for continuing development of turbulence models, stability codes, and high performance aerodynamic design. Data in this report include: the variation in transition location with Reynolds number in the boundary layer of a two-dimensional high speed natural laminar flow airfoil (HSNLF) model; additional bypass mechanisms present, such as surface roughness elements; and, shock-boundary layer interaction. Because of the early onset of turbulent flow due to surface roughness elements present in testing, it was found that elements from all these data were necessary for a complete analysis of the boundary layer for the HSNLF model.

Following the satellite-level thermal vacuum test for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation spacecraft, project thermal engineers determined that the radiator used to cool the Integrated Lidar Transmitter subsystem during its operation was oversized. In addition, the thermal team also determined that the operational heaters were undersized, thus creating two related problems. Without the benefit of an additional thermal vacuum test, it was necessary to develop and prove by analysis a laser temperature control scheme using the available resources within the spacecraft along with proper resizing of the radiator. A resizing methodology and new laser temperature control scheme were devised that allowed, with a minimum of 20% heater power margin, the operating laser to maintain temperature at the preferable set point. This control scheme provided a solution to a critical project problem.

A procedure is developed for evaluating various candidates for thermal control in the orbiting space station. Candidates for acquisition, transport and rejection are considered. For example, thermal rejection candidates include heat pipe radiators, high capacity heat pipe radiators and liquid droplet raditors. A computer program has been developed which computes subsystem and total system weights, volumes, powers and costs for a system consisting of selected acquisition, transport and rejection candidates. The program user is also able to select mission parameters such as duration, resupply interval, thermal loads, transport distance, acquisition temperature and rejection temperature. Simulation models are included in the program which allow the user to change candidate designs. For example, for a high capacity heat pipe radiator the user may change working fluid, materials, radiator temperature, radiator geometry, surface emissivity and surface absorptivity.