Thermal and Mechanical Characteristics of a Multifunctional Thermal Energy Storage Structure
Thermal energy storage (TES) sandwich-structures that combine the heat storage function with structural functionality are described. The structure consists of a thermal interface (TI) connected to a hollow plate lamination. Each laminate is a hollow aluminum plate having a series of mm-scale channels or compartments that are filled with phase change material (PCM). Heat storage is via the latent heat of the PCM. A generalized thermal response model that is applicable to a wide range of channel geometrical configurations is described. The model couples the thermal response of the TI to the hollow aluminum plate/PCM-volume. The temporal response of the system is easily obtained via numerical solution of two ordinary differential equations, which can be solved to give closed-form solutions subject to a simple assumption. Thermal analysis delineates geometrical configurations that have good thermal response characteristics. The mechanical properties of the laminated structure are determined experimentally. Four-point bending experiments are conducted using specimens made with three layers of hollow plates laminated using a structural adhesive. An energy method is developed to model both the deformation and strength of the laminated structure. The energy method is developed based on the assumption that plane cross sections of the structure remain plane under bending, a condition that is valid for both linear and nonlinear materials. The energy method can provide deformation of the aluminum laminates comparable with the experiments. Experiments and modeling indicate that these laminated structures have an excellent performance-to-weight ratio.
NON-METALLIC AND STRUCTURALLY EFFICIENT THERMAL ENERGY STORAGE COMPOSITES FOR AVIONICS TEMPERATURE CONTROL, PART II: MECHANICAL CHARACTERIZATION.
Mechanical characterization of a two-dimensional Thermal Energy Storage (TES) composite structure that combines the heat storage capability with structural functionality was carried out experimentally. Static and fatigue experiments were conducted for the composite structure under three-point bending at both room temperature and elevated temperature. An energy method model was developed to predict the mechanical behavior of the composite. Nomenclature E Young's modulus M Bending moment P External load applied e Strain es Surface strain σ Stress δ Deflection ∆e Strain increment ∆U Strain Energy increment ∆δ Deflection increment ∆W Work increment yc Position of the neutral axis
Methodology for Designing a Hybrid Thermal Energy Storage Heat Sink

 A thermal response model for designing a hybrid thermal energy storage (TES) heat sink is developed. The stabilization time and maximum operating (hot side) temperature-to-transition temperature difference are used to characterize the performance of the heat sink. The thermal properties of the PCM employed in the design are investigated. Integration of a design optimization algorithm into a thermal performance model of the TES-hybrid heat sink results in determination of a best design subject to geometric and heat loading constraints. A prototype based on this best design is build and used to benchmark the performance model. The performance measured is consistent with the simulation model predictions of performance.