Thermo-Mechanical Simulations of Rear Lamps with CFD

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A complete methodology for the thermo-mechanical analysis
of optical devices for the automotive industry is presented.
The objective is to predict the thermal field all over the lamp,
highlighting the zones with risk of melting, and the
deformations and stresses associated with it. The proposed
approach is based on a Computational Fluid-Dynamic (CFD)
simulation capable of capturing all the heat transfer
phenomena occurring inside and outside the lamp:
conduction between different components of the device,
natural convection associated with density changes in air
(buoyancy effects), and radiation heat transfer. The latter
requires a fairly complex modeling strategy in order to
provide a satisfactory (and conservative) treatment for the
source of power, i.e. the filament, which can be obtained by
means of a proper inclusion of transparency. The radiation
model is verified according to a theoretical-numerical
comparison on a schematic test case; the whole methodology
is then validated on a simple prototype of lamp with the aid
of experimental investigations. For a more accurate
description of the boundary conditions for the lamp, it is
possible to include the external environment, on which
natural convection arises too. The treatment of unsteady
simulations is discussed, with the description of a suitable
adaptive timestep algorithm capable of reducing the
computational costs and thus keeping the simulation feasible.
The whole methodology is finally tested on a complex industrial lamp.

Author Name: 
Flavio Cimolin
Michele Rabito
Andrea Menotti
Conference Location: 
Detroit, MI, USA
Rights: 
2011 SAE International
Conference Date: 
Tuesday, April 12, 2011
Paper Reference: 
2011-01-0109
Publisher: 
SAE International
DOI: 
http://dx.doi.org/10.4271/2011-01-0109
Conference Name: 
SAE 2011 World Congress & Exhibition