Design, Manufacturing and Testing of a Novel Aperture-Cavity System for Enhanced Solar Reactor Technology
(1) a camera-like variable aperture, and
Emission free co-production of carbon nanotubes and hydrogen via concentrated solar energy
(1) develop two-phase, 3D, unsteady CFD models including kinetics, heat transfer, and incoming solar flux for a 1kW solar reactor,
(2) design and construction of an experimental setup to verify that the flow field of the reactor predicted by the CFD simulations is correct,
(3) manufacture and operation of 1kW reactor,
Thermal dilation and internal damage of cryogenic concrete utilized for direct liquefied natural gas containment
Utilization of concrete for direct liquefied natural gas (LNG) containment could dramatically reduce the cost of constructing LNG storage facilities, but currently there are important areas of missing data and a lack of fundamental understanding of concrete behavior at cryogenic temperatures. Understanding concrete behavior at cryogenic temperatures is critical for the design of concrete LNG storage tanks. In particular, the coefficient of thermal dilation (CTD) and the development of damage due to differential CTD at cryogenic temperatures have not been systematically studied and are not well understood. The control of the CTD is critical because the incorrect CTD could result in structural damage as concrete is cooled, while the development of damage enhances the transport rate of LNG through concrete. There are three primary objectives for the proposed project. First, the CTD of concrete at cryogenic temperatures will be measured and modeled as a function of the mixture design and concrete component constitutive properties. Second, the damage that develops in cryogenic concrete due to CTD mismatch will be modeled as a function of mixture design and concrete component constitutive properties using computational damage mechanics. Finally, based on the experimental and modeling results, guidelines will be developed for designing cryogenic concrete with respect to control of the CTD and minimization of internal damage.
Automated identification of subsea architectures via reduced order modeling
Offshore petroleum exploration and production is becoming the key source of energy. Reliably retrieving this oil and natural gas in a cost effective manner entails engineering challenges that are significant. The fundamental subsea architecture problem centers on specifying pipelines (locations, insulation, sizing), risers, manifolds, valving and possible artificial lift systems (subsea pumps and motors) given reservoir locations and pressures/temperatures. This fundamental problem in deepwater energy production will be approached as a multi-physics system-of-systems. The phases of the proposed research include:
(1) identification of reduced order mechanical, thermal (hydrates) and fluid dynamic models of subsea subsystems (pipelines, manifolds, valve, etc),
(2) automated self-assembly of the reduced order models using a system-of-systems approach,
(3) subsea architecture identification based on cost and reliability, and
(4) the design of a multivariable controller for subsea systems integration. The proposed research team has a proven productive research collaboration on energy utilization sponsored by QNRF.
Solar Hybrid Hydrogen Production Cycle with In-situ Thermal Energy Storage
The program of research and development of a solar-powered water splitting cycle (WSC) with in-situ thermal energy storage using concentrated solar energy is proposed. The approach involves a hybrid photo-thermochemical WSC that combines a photochemical hydrogen production step with a high-temperature thermochemical oxygen evolution step to accomplish water splitting. The proposed cycle represents the modification of the Sulfur-family thermochemical WSC with three distinct innovations:
(1) A unique photocatalytic step that generates hydrogen using visible part of the solar spectrum,
(2) A novel O2 evolution half-cycle incorporating an in-line thermal storage that utilizes the same molten salt reagents that are used in the cycle, and
(3) All fluidic operation (no solids are involved). The work will involve extensive process simulation and chemical plant analyses efforts (Aspen+, etc), as well as experimental studies of the photocatalytic and thermochemical stages of the hybrid WSC.
Micro-Nano Fluid Mechanics
There has been a growing trend in energy generation and consumption in industrial systems in the last century. Power density of engineering systems has increased significantly as a result of miniaturization in a variety of fields. This has led to the development and design of better cooling methods for these systems. Phase change cooling methodologies such as spray cooling are among the best ways to manage heat transfer in high thermal loads applications. However, the physical mechanisms of spray cooling are still insufficiently understood due to the vast number of variables involved in its hydrodynamics. The objectives of this work are to investigate the effects of droplet physical parameters such as droplet size and frequency on Kevin-Helmholtz instability suppression and convective heat transfer enhancement on the surface by inducing fine-tuned capillary waves through periodic droplet impingement.
Rapid increase in power density due to progressive miniaturization in advanced technology platforms has led to the need for smarter, cheaper, and more efficient cooling methods. Promising developments in nanotechnology can provide novel solutions for mitigating the enhanced heat fluxes and can be easily retrofitted to existing cooling platforms. Nanofluids, engineered colloidal suspensions of 5-100 nanometer sized particle suspended in a base fluid, have been in limelight in this century due to the anomalous enhanced heat transfer capabilities. However, the physical mechanisms for the reported enhancements are not yet clear. Researchers from all around the world have tried to propose various theories to explain this phenomenon; however, there is a lack of experimental data for nanofluids at nanoscale. The goal of this proposal is to understand the physical interactions during forced convection in micro/nano-fluidic systems and on engineered surface nano-structures (“nano-fins”) using novel experimental methods and state of the art facility at Texas A&M at Qatar.
Energy Efficient Systems
This project seeks to investigate at both the thermal-hydraulic (heat transfer and fluid dynamics) behavior of supercritical fluids in a horizontal pipe. Convective heat transfer coefficient of fluids at supercritical pressures has many special features when compared to those at both single and two phase fluids due to the rapid changes of thermophysical properties in this region. The momentum and energy equations are strongly coupled as large variations of the fluid density causes the flow to accelerate or decelerate, which in turn affects the heat transfer. Consequently, the heat transfer correlations and models used for typical fluids are not generally applicable to supercritical conditions. This project in Texas A&M University Qatar funded by Qatar Foundation seeks to experimentally investigate, at both the fundamental and applied levels, the heat transfer and fluid dynamics behavior of supercritical fluids. The supercritical CO2 testing facility built in Micro Scale Thermo Fluids (MSTF) Laboratory in Texas A&M University at Qatar is especially designed for investigating thermal and hydraulic behavior of CO2 fluid flow near its critical point.
Environment and Renewable Energy