Project Description

The automotive industry has been increasingly challenged to invest heavily in innovative
powertrain technologies. These advancements can result in a complex array of tunable
control parameters to optimize engine performance over a range of operating conditions.
Hence, the calibration process of a modern passenger car diesel engine consumes significant
time, effort and resources, making it a bottleneck during the development process. Advanced
modeling tools, such as CFD, are often used with the goal of streamlining portions of the
calibration process. The usefulness of CFD simulations tools for in-cylinder engine
combustion is often compromised by the computational overhead of detailed chemical
kinetics and uncertainty in the combustion chamber wall temperatures. Specifically,
traditional diesel engine CFD simulations consist of partial geometry sector mesh
computations utilizing reduced order kinetics mechanisms, fixed spatially uniform wall
temperature boundary conditions, and a prescribed solid body swirl velocity field prior to
spray injection in lieu of computing air induction with valve motion. The proposed research
seeks to leverage recent advancements in CFD to improve the accuracy CFD computations
and accelerate engine calibration. First, higher order kinetics will be solved using a GPUbased
chemical kinetics solver (leveraged in past ALCC awards CMB119 and CMB124). Next,
full in-cylinder 3D spray, flow and combustion simulations will be undertaken considering
conjugate heat transfer to predict temporally and spatially varying wall temperature
boundary conditions. The results will be analyzed to compare differences in combustion and
emissions (NOx, CO, UBHC, Smoke) with actual engine measurements.

Allocation History

Source Hours Start Date End Date