Search NASA⌕ Search

Engineering topics

Hotchkiss, G. B.

Publications and source records attributed to Hotchkiss, G. B..

3 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Solar collector parameter identification from unsteady data by a discrete-gradient optimization algorithm

A discrete-gradient optimization algorithm is used to identify the parameters in a one-node and a two-node capacitance model of a flat-plate collector. Collector parameters are first obtained by a linear-least-squares fit to steady state data. These parameters, together with the collector heat capacitances, are then determined from unsteady data by use of the discrete-gradient optimization algorithm with less than 10 percent deviation from the steady state determination. All data were obtained in the indoor solar simulator at the NASA Lewis Research Center.

Hotchkiss, G. B.↗
NASA NTRS1979

Spectral effects on direct-insolation absorptance of five collector coatings

Absorptances for direct insolation of black chrome, black nickel, copper oxide, and two black zinc conversion selective coatings were calculated for a number of typical solar spectrums. Measured spectral reflectances were used while the effects of atmospheric ozone density, turbidity, and air mass were incorporated in calculated direct solar spectrums. Absorptance variation for direct insolation was found to be of the order of 1 percent for a typical range of clear-sky atmospheric conditions.

Hotchkiss, G. B.↗
NASA NTRS1979

A mobile apparatus for solar collector testing

The design, construction, and operation of a mobile apparatus for solar collector testing (MASCOT) is described. The MASCOT is a self-contained test unit costing about $10,000 whose only external requirement for operation is electrical power and which is capable of testing two water-cooled flat-plate solar collectors simultaneously. The MASCOT is small enough and light enough to be transported to any geographical site for outdoor tests at the location of collector usage. It has been used in both indoor solar simulator tests and outdoor tests.

Hotchkiss, G. B.↗