CFD Modeling of Thermoelectric Air Duct System for Cooling of Building Envelope

A multi-stage of thermoelectric modules is used in an air duct as a cooling system. The ThermoElectric Air Duct (TE-AD) system is installed with 24 ThermoElectric Modules (TEMs) installed with heat sink, cold plate and exhaust fan for air circulation. To simplify the TE-AD system, a three-dimensional model is proposed and implemented in a Computational Fluid Dynamics (CFD) simulation environment (FLUENT). An analysis of results, obtained in the experimental study of the TE-AD system for cooling of building envelope, shows that temperature gradient of 3.0-5.3°C between interior and the exterior of the building envelope was achieved. The current supplied to the TEMs are constant while the air flow rate is varied to investigate the factor on the performance of the thermoelectric. Using the TE-AD simulation model, it can be implemented to various CFD models of heat sources to predict the system performance for optimization

High Efficiency Polymer based Direct Multi-jet Impingement Cooling Solution for High Power Devices

Liquid jet impingement cooling is an efficient cooling technique where the liquid coolant is directly ejected from nozzles on the chip backside resulting in a high cooling efficiency due to the absence of the TIM and the lateral temperature gradient. In literature, several Si-fabrication based impingement coolers with nozzle diameters of a few distributed returns or combination of micro-channels and impingement nozzles. The drawback of this Si processing of the cooler is the high fabrication cost. Other fabrication methods for nozzle diameters for ceramic and metal. Low cost fabrication methods, including injection molding and 3D printing have been introduced for much larger nozzle diameters (mm range) with larger cooler dimensions. These dimensions and processes are however not compatible with the chip packaging process flow. This PhD focuses on the modeling, design, fabrication and characterization of a micro-scale liquid impingement cooler using advanced, yet cost efficient, fabrication techniques. The main objectives are: (a) development of a modeling methodology to optimize the cooler geometry; (b) exploring low cost fabrication methods for the package level impingement jet cooler; (c) experimental thermal and hydraulic characterization and analysis of the fabricated coolers; (d) applying the direct impingement jet cooling solutions to different applications

Thermal Characteristics and Safety Aspects of Lithium-Ion Batteries: An In-Depth Review

This paper provides an overview of the significance of precise thermal analysis in the context of lithium-ion battery systems. It underscores the requirement for additional research to create efficient methodologies for modeling and controlling thermal properties, with the ultimate goal of enhancing both the safety and performance of Li-ion batteries. The interaction between temperature regulation and lithium-ion batteries is pivotal due to the intrinsic heat generation within these energy storage systems. A profound understanding of the thermal behaviors exhibited by lithium-ion batteries, along with the implementation of advanced temperature control strategies for battery packs, remains a critical pursuit. Utilizing tailored models to dissect the thermal dynamics of lithium-ion batteries significantly enhances our comprehension of their thermal management across a wide range of operational scenarios. This comprehensive review systematically explores diverse research endeavors that employ simulations and models to unravel intricate thermal characteristics, behavioral nuances, and potential runaway incidents associated with lithium-ion batteries. The primary objective of this review is to underscore the effectiveness of employed characterization methodologies and emphasize the pivotal roles that key parameters—specifically, current rate and temperature—play in shaping thermal dynamics. Notably, the enhancement of thermal design systems is often more feasible than direct alterations to the lithium-ion battery designs themselves. As a result, this thermal review primarily focuses on the realm of thermal systems. The synthesized insights offer a panoramic overview of research findings, with a deeper understanding requiring consultation of specific published studies and their corresponding modeling endeavors

Modeling fabrication and characterization of a bio-micro thermoelectric device for highly localized temperature control

There is an ever expanding interaction between the fields of micro-electromechanical systems (MEMS) and biology to develop devices to monitor, control and act on living systems. Particularly in the field of cryobiology, there is a need to monitor and control temperature at the cellular level. An important step towards achieving this aim is to fabricate an array of microscale thermoelectric actuators. As a first step for towards achieving such localized control of temperatures in cells and tissues, an array of individually addressable micro-thermoelectric coolers (µTECs) were modeled, characterized, and fabricated. Prefabrication experimentation and modeling were carried out to understand the behavior of the device. Two mathematical models, the lumped parameter model and finite element model, were used to identify important device parameters and dimensions. The organization of the proposed device was an array of 4 x 4 microscale (~10 ìm) thermoelectric actuators, each of which was separated by a distance of 50 ìm center-to-center and dimensioned so that each µTEC could measure or modulate the temperature in the neighborhood of a single cell. The prefabrication experiments showed that it was feasible to produce the TECs required for fabrication of the device through electrodeposition. Bismuth-telluride was electrodeposited to form the n-type and p-type leg elements of µTEC and the deposition was achieved by varying the cathodic potential. The material deposition development could focus on a single material system, yielding both n-type, and p-type pellets of TEC. The prototype devices were successfully fabricated with a modified multi-step LIGA (Lithographie, Galvanoformung and Abformung) technique wherein a patterned positive photoresist and photomasks defined the geometry of the device. This enables high-density wiring required for the device. In future, these µTECs will be embedded in Polymethylmethacrylate (PMMA) matrix to improve insulation. An artificial tissue (AT) system composed of Normal Human Dermal Fibroblast (NHDF) cells from stem cells will be grown on the device for experimentation wherein a PMMA sheet will act as an interface between the cooler and the embedded cells. The thermoelectric micro device thus developed will result in the unique capability of temperature manipulation and control on cellular scales (micrometers)

2020 NASA Technology Taxonomy

This document is an update (new photos used) of the PDF version of the 2020 NASA Technology Taxonomy that will be available to download on the OCT Public Website. The updated 2020 NASA Technology Taxonomy, or "technology dictionary", uses a technology discipline based approach that realigns like-technologies independent of their application within the NASA mission portfolio. This tool is meant to serve as a common technology discipline-based communication tool across the agency and with its partners in other government agencies, academia, industry, and across the world

NASA SBIR abstracts of 1990 phase 1 projects

The research objectives of the 280 projects placed under contract in the National Aeronautics and Space Administration (NASA) 1990 Small Business Innovation Research (SBIR) Phase 1 program are described. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses in response to NASA's 1990 SBIR Phase 1 Program Solicitation. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 280, in order of its appearance in the body of the report. The document also includes Appendixes to provide additional information about the SBIR program and permit cross-reference in the 1990 Phase 1 projects by company name, location by state, principal investigator, NASA field center responsible for management of each project, and NASA contract number

CFD Modeling of Thermoelectric Air Duct System for Cooling of Building Envelope

A multi-stage of thermoelectric modules is used in an air duct as a cooling system. The ThermoElectric Air Duct (TE-AD) system is installed with 24 ThermoElectric Modules (TEMs) installed with heat sink, cold plate and exhaust fan for air circulation. To simplify the TE-AD system, a three-dimensional model is proposed and implemented in a Computational Fluid Dynamics (CFD) simulation environment (FLUENT). An analysis of results, obtained in the experimental study of the TE-AD system for cooling of building envelope, shows that temperature gradient of 3.0-5.3°C between interior and the exterior of the building envelope was achieved. The current supplied to the TEMs are constant while the air flow rate is varied to investigate the factor on the performance of the thermoelectric. Using the TE-AD simulation model, it can be implemented to various CFD models of heat sources to predict the system performance for optimization