22
industry, working with software developers, is engaging in more and more simulation studies,
with much of the work being design-specific and proprietary. A comprehensive computer code to
predict fuel economy and emissions for an entire drive cycle, including modules for the power-
train, vehicle-load prediction, control systems, cooling systems, external aerodynamics,
underhood airflow, cooling and refrigeration, lubricant cooling, and cabin airflow is needed for
optimizing future designs. Recommended subtask activities include the following:
·
Development of a nonproprietary system code of zero or one dimension to run
on a PC; the initial task would be a paper study to determine what is already
available (e.g., codes, submodels, and validation data) and what the
automobile industry is doing.
·
Development/demonstration/validation of CFD models and simulation codes
for underhood airflow and temperatures, for use in integrating heat
exchangers.
·
Integration of computer models for underhood airflow with codes developed
for aerodynamic drag prediction [6], and demonstration of the use of such
integrated codes to optimize airflow for cooling (heat exchanger efficiency)
and aerodynamic drag reduction.
·
Collaboration with code developers, OEMs, and suppliers to develop a
consistent interface specification so that data can be efficiently transferred
between codes and code modules.
·
Development of the framework for a simulation code that ultimately can be
used to predict truck fuel economy and emissions for an entire drive cycle.
Task 5: Sensors and Control Components Development. This task will identify sensor
and control requirements of an advanced computer-controlled thermal-management system,
evaluate what sensors and controls are available to satisfy these needs, and identify research
needed for development of new, more accurate and robust sensors and controls. A computer-
controlled thermal management system with demand-responsive control and supply of mass and
heat flows to maintain critical engine and engine-related component temperatures within
acceptable ranges is a goal of the industry. Such a system requires sensors, actuators,
microprocessors, and control algorithms. Sensors are required to measure such parameters as
temperature, pressure, and flow rates at critical points in the engine and in the air and coolant
circuits. The operating conditions of the engine (speed and torque), fan and pump speeds, and
ambient temperature must also be measured. These measured parameters, together with input
signals from other components and/or operator commands, would be input to a microprocessor-
based control system. The cooling system actuators (valves, and variable-speed pump and fan)
would be controlled according to prescribed control objectives. It is important to have requisite
sensors and controls available to implement advanced concepts. A reliable and robust real-time