Engineering topics

Joshi, N. D.

Publications and source records attributed to Joshi, N. D..

3 records

NASA NTRS1987

Particle cloud kinetics in microgravity

Data related to particle-particle agglomeration/deaglomeration and particle-wall attachment are discussed. Particle-cluster cloud interactions and particle-cluster agglomeration/deagglomeration kinetics are studied. An apparatus designed and constructed for examining the agglomeration/deagglomeration effects for lycopodium under the conditions of an acoustically energized mixing process and of alpha-particle-induced deagglomerative processes is described; characteristic features and applications for the apparatus are examined. Requirements for combustion experimentation are discussed.

Berlad, A. L.↗

NASA NTRS1986

Flame propagation and extinction in particle clouds

Two phase flame propagation and extinction theory required to support the corresponding experiments planned for the space shuttle is being developed. Also being planned are specialized collaborative, experimental and theoretical NASA UCSD studies needed to support the ongoing definition of needed experimental hardware, experimental procedures, data acquisition philosophy, and other ground based support activities required to assure the success of space shuttle based experiments concerned with combustion of clouds of particulates at reduced gravitational conditions. The further development of relations delineating premixed particle cloud and premixed gaseous systems as well as burner stabilized and freely propagating flame systems is considered.

Berlad, A. L.↗

NASA NTRS1984

Gravitational effects on the extinction conditions for premixed flames

The four particular classes of premixed flames which are of special interest include freely propagating gaseous flames, burner stabilized premixed gaseous flames, freely propagating particle-cloud flames, and burner stabilized two-phase flames. Associated gravitational effects are related to upward flame propagation, downward flame propagation, and flame propagation in microgravity. The results of theoretical and experimental studies suggest that a comprehensive approach to representation of extinction limits must deal with the full range of existence limits observed for flames. Issues awaiting solution are related to the flammability limits, extinction limit relations, and flame theories for g = 0. Attention is given to theoretical considerations, nonadiabatic features of premixed lycopodium-air flames, and general comments on the extinction conditions for premixed flames.

Berlad, A. L.↗