Thomas P. Gielda

Design and manufacturing of two thermal observation manikins for automobile applications.

Two state-of-the-art thermal observation manikins were designed and built for use in automobile applications. These manikins not only apply the latest data acquisition and control technology but also incorporate new manufacturing and sensor technology for improved performance. The manikins are equipped with 26 segments that can be easily removed for maintenance and replacement. Furthermore, their unique design offers an important and a major improvement over previous manikin designs by incorporating heat flux transducers (HFTs) to measure heat gain when exposed to external heating conditions. The HFTs provide these manikins the ability to measure heat flux to or from the environment, regardless of segment skin temperature. The end goal for these manikins is to incorporate a subjective model of thermal comfort along with a human thermal physiological model to produce a thermal sensation vote based on a combination of HFTs, temperature sensors, and heater power measurements. This paper discusses the need for two identical research quality thermal manikins and presents the details of the design and construction of two identical thermal manikins and the associated data acquisition and control software.

Scaled Room Three-Dimensional Computational Fluid Dynamics Simulations

Computational fluid dynamics (CFD) simulations were used to predict three-dimensional flow within a one-tenth-scale room. The dimensions of the scaled room were 732 × 488 × 274 mm (28.8 × 19.2 × 10.8 in.) and symmetry was utilized so that only half of the room was modeled. Corresponding measurements were made under isothermal conditions and water was used as the working fluid instead of air. The commercially available software Fluent was used to perform the simulations. Two turbulence models were used: the renormalization group (RNG) k-e model and the Reynolds-stress model. The CFD setup is presented in this paper, along with the velocity and turbulent kinetic energy results. The simulation results are compared to previously obtained three-dimensional particle image velocimetry (PIV) measurements made within the same scaled room under similar conditions.Copyright

Energetic and CFD Modeling Considerations of Thermal Management

An up front CAE coupling of tools is described which provides for routine thermal flow analysis of vehicle powertrain cooling systems for a variety of vehicle shapes and sizes. A family of parametric models is generated using Pro/E which allows for flexible representation of a variety of vehicle classes with accurate thermal flow analyses. The parametric CAD models are morphed to model the important flow features in a relatively complex underhood vehicle model. Some detailed modeling is often added to the generic parametric model for flexibility in modeling important unique details. All tetrahedra meshes are generated automatically from the CAD model using Simmetrix software. High aspect ratio elements are layered near appropriate surfaces for appropriate modeling of shear layers. Templates are used for exporting the mesh and flow simulation parameters to the flow solver, AcuSolve. An unsteady, incompressible air flow with energy equation and Spalart-Almaras turbulence model is used underhood and around the vehicle with simple heat exchanger models and coupled radiation. The flow through grille opening elements is modeled with detailed surfaces and appropriate grid resolution of flow. An adaptation technique using an a posteriori approach is demonstrated. Comparison to test data shows good correlation for a variety of steady and unsteady cases.

Scaled Room Three-Dimensional Velocity Measurements Using Particle Image Velocimetry

A stereoscopic particle image velocimetry (PIV) system was used to measure flow within a one-tenth-scale room. The dimensions of the scaled room were 732 × 488 × 274 mm (28.8 × 19.2 × 10.8 in.). The measurements were made under isothermal conditions and water was used as the fluid instead of air. Six equally spaced vertical planes along the length of the room were captured and symmetry was utilized so that measurements were only made on one side of the room. A sample size of 50 pairs of PIV images were collected and averaged to determine average velocity. Turbulent kinetic energy was also calculated from the collected data. The equipment configuration, measurement information and the velocity and turbulent kinetic energy results are presented in this paper. The measurements provide detailed three dimensional velocity profiles that could be used to validate numerical simulations.Copyright