Engineering Commons^™

Multiphysics Diesel Aftertreatment System Modeling For Reduced Emissions From Hybrid Electric Heavy-Duty Powertrains, Uday Srivastav

All Theses

Hybridization of heavy-duty on-road vehicles presents an opportunity to significantly reduce internal combustion engine emissions in real-world operation. These gains can be realized through the coordination of the electric drive, engine, and aftertreatment systems. Accurate Multiphysics models of all powertrains sub-systems are required to achieve the goal of reduced emissions. This research aims to develop a model of a highly complex diesel engine aftertreatment system. This study focuses on utilizing transient data for calibration and validation of the aftertreatment system and reducing the run time when compared to real-time experiments. The calibration focuses on two physical phenomena, thermal behavior and …

Development And Validation Of An Analytical Modeling Tool For Solar Borehole Heat Exchangers, Adam Ornelles

All Theses

Current numerical modeling solutions used for subsurface heat flow, such as the Berkeley TOUGH codes, are often difficult to use and time-consuming compared to analytical modeling methods. However, current analytical modeling methods for subsurface heat flow and groundwater cannot accurately model the subsurface in 3 dimensions, a feature paramount to the planning and installation of thermal borehole heat exchangers used in environmental remediation.

This research developed a novel 3-dimensional analytical modeling tool for solar-powered borehole heat exchangers. The analytical modeling tool can plan thermal remediation systems while being more straightforward to operate than current numerical modeling software. By creating a …

Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan

All Theses

Growing fresh water needs have led to an interest in water desalination using reverse osmosis (RO) membranes. Energy consumption has a large share in the expenses incurred to drive a reverse osmosis desalination system. With depleting fossil fuel reserves, tapping renewable sources of energy is a promising alternative to meet the energy requirements. Wind power coupled to an RO desalination system is a potential means of delivering clean water using sustainable energy. This work investigates modeling of a conceptual wind-energy-driven RO desalination system that is made possible because of an air-pressure energy storage mechanism. Bench-scale experiments were performed on an …

Determining Transverse Design Forces For A Next-D Bridge Using 3d Finite Element Modeling, Robert Funcik

All Theses

This thesis looks into the use of 3D Finite Element Modeling to determine the transverse design forces for short-span bridges built using the Northeast Extreme Tee with integral deck (NEXT-D) beam. Models were built using either solid elements or shell elements to represent the bridge deck, and the results were compared. The stiffness of the shear keys were taken into account during the modeling process. Results were compared to the AASHTO strip width method for design bridge decks, and the results showed that the strip width method would not be adequate for the design of NEXT-D bridges, so specific live …

A New Approach To Dynamic Modeling Of Continuum Robots, Nivedhitha Giri

All Theses

ABSTRACT
In this thesis, a new approach for developing practically realizable dynamic models for continuum robots is proposed. Based on the new dynamic models developed, a novel technique for analyzing the capabilities of continuum manipulators to be employed in various real world applications has also been proposed and developed.
A section of a continuum arm is modeled using lumped model elements (masses, springs and dampers). It is shown that this model, although an approximation to a continuum structure, can be used to conveniently analyze the dynamics of the arm with suitable tradeoff in accuracy of modeling. This relatively simple model …

A Numerical And Experimental Study Of Differential Settling In Cohesive Sediment, Chad Heiliger

All Theses

Accurate sedimentation modeling has important applications in a number of fields. This includes modeling the accumulation of sediment in harbor channels and modeling the sedimentation and accumulation of particles in retention ponds in the still waters behind dams in order to calculate the trap efficiency. By accurately modeling sedimentation, engineering failures such as the 2008 TVA spill at the Kingston Fossil Plant could possibly be avoided. Three different numerical models comparing the settling rates of individual particles in quiescent waters were created to compare the change of settling velocity due to particle size distributions, change of local concentrations, and flocculation …