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only a final product and this could be a true cost savings to manufacturers. There were
also questions of why DOE would have an interest in this area and suggestions that
perhaps DOE should push for changes in the regulatory climate. That would have greater
impact on the overall efficiency of heavy vehicles than support for any technical change
that would, at best, create only marginal efficiencies.
also questions of why DOE would have an interest in this area and suggestions that
perhaps DOE should push for changes in the regulatory climate. That would have greater
impact on the overall efficiency of heavy vehicles than support for any technical change
that would, at best, create only marginal efficiencies.
There was some discussion of the role of new materials in changing the thermal
efficiency of heavy vehicles. While somewhat removed from the main thrust of the
session, it was felt that new materials and the simulation of their effect on heat-transport
systems was an area deserving consideration. Only the large integrated companies (e.g.,
CAT) would be interested in this, however, since they are the only ones with a broad
enough view to see the impact on a total system basis.
session, it was felt that new materials and the simulation of their effect on heat-transport
systems was an area deserving consideration. Only the large integrated companies (e.g.,
CAT) would be interested in this, however, since they are the only ones with a broad
enough view to see the impact on a total system basis.
The subject of how compact heat exchangers and new materials could be
combined also was discussed. This combination could have a significant effect on new
truck designs particularly front-end designs through alterations in both internal air flow
and external aerodynamics. In a similar way, improved fans and fan packaging could alter
truck design. It was felt that DOE could be of value in developing advanced design
methods for fans and in providing the basic flow data needed to validate fan-design
methodology.
truck designs particularly front-end designs through alterations in both internal air flow
and external aerodynamics. In a similar way, improved fans and fan packaging could alter
truck design. It was felt that DOE could be of value in developing advanced design
methods for fans and in providing the basic flow data needed to validate fan-design
methodology.
There is a real need to better understand phase-change systems, both in HVAC
packages and in engine heat transfer. This could include nucleate boiling in engine
cooling passages, the effect of vibration on phase behavior, the generation of wear
(pitting) by bubble collapse, etc. This is an area where there could be two major points of
focus. For some systems, it would be best to concentrate on prevention of boiling under
any operating condition this would be for trucks similar to those now in service. For the
next generation, the control of nucleate boiling through detection sensors and computer
control of flow would be a way to produce more efficient systems that could, for short
periods of intense loading, operate safety in thermal regimes not now possible.
cooling passages, the effect of vibration on phase behavior, the generation of wear
(pitting) by bubble collapse, etc. This is an area where there could be two major points of
focus. For some systems, it would be best to concentrate on prevention of boiling under
any operating condition this would be for trucks similar to those now in service. For the
next generation, the control of nucleate boiling through detection sensors and computer
control of flow would be a way to produce more efficient systems that could, for short
periods of intense loading, operate safety in thermal regimes not now possible.
The group did not come up with a definitive list of recommendations; however,
the topics that were considered of interest in the general area of modeling and simulation
were the following (not in any priority order):
were the following (not in any priority order):
·
Development of a generic (open literature) system code of zero or one
dimension.
dimension.
·
Creation of an experimental database on thermal performance of
systems and subcomponents that could be used for code validation.
systems and subcomponents that could be used for code validation.
·
Study of phase change, boiling, and condensation, in geometries and
under conditions typical of heavy-vehicle design. This would provide
under conditions typical of heavy-vehicle design. This would provide