Dd. Hall et I. Mudawar, EXPERIMENTAL AND NUMERICAL STUDY OF QUENCHING COMPLEX-SHAPED METALLICALLOYS WITH MULTIPLE, OVERLAPPING SPRAYS, International journal of heat and mass transfer, 38(7), 1995, pp. 1201-1216
The present study constitutes a crucial step towards the development o
f a CAD based intelligent spray quenching system capable of optimizing
the mechanical properties (strength, hardness) of age-hardenable alum
inum alloys. The quenching of an L-shaped aluminum alloy with multiple
, partially overlapping spray nozzles was successfully modeled using t
he finite element method. Spray heat transfer correlations, which rela
te the local heat transfer rate in each of the boiling regimes experie
nced by the surface to the local values of the spray hydrodynamic para
meters (volumetric spray flux, mean drop diameter, mean drop velocity)
, were used as boundary conditions. The spatial distributions of the s
pray hydrodynamic parameters were modeled and incorporated into the fi
nite element program. Axial nonuniformity in the heal transfer coeffic
ient along the surfaces of long extrusions, which can lead to unwanted
residual stresses, was eliminated by developing a method for optimizi
ng the distance between adjacent nozzles. The numerical results were e
xperimentally verified in a simulated industrial environment. This stu
dy is the first successful attempt at systematically predicting the te
mperature response of a quenched part from knowledge of only the part
geometry and spray nozzle configuration. Integration of the finite ele
ment program with an optimization routine will yield a system capable
of selecting the appropriate spray nozzle configuration for a new part
prior to production; thus, achieving superior part quality without co
nducting costly experimental tests.