Mechanical Engineering Commons^™

Combustion Of Aerosolized Spherical Aluminum Powders And Flakes In Air, Binu Zacharia Eapen

Theses

Combustion rates and completeness of aerosolized spherical aluminum powders and flakes are compared using constant volume explosion experiments. The comparison of particles and flake sizes was made based on their specific surface areas determined using the Brunauer-Emmett-Teller (BET) method and respective "BET diameters". It is observed that the rates of pressure rise and rates of flame propagation were higher for aluminum powders with BET diameters of about 2 to 5 μm compared to aluminum flakes for which the BET diameters were under 1 μm In agreement with the flame propagation rates, the overall completeness of combustion was also higher for …

Magneto-Rheological Fluid Orthosis For Suppressing Tremor, Hyoung-Joo Yeo

Theses

Tremor is a common movement disorder that occurs with specific neurological conditions. This condition may seriously impact daily living activities. The aim of the present study is to evaluate the possibility of the development of a wearable technology that is capable of exerting torques at a user's joints for suppressing tremor.

This thesis is based on the concept of "smart structures" which are made of Magneto-Rheological (MR) fluid that can dynamically alter its viscosity under magnetic field. The wearable tremor suppressing orthosis needs several conditions. It should be safe, light weight, simple and small in structure, and easily attachable. An …

Characterization Of Aluminum Powder Ignition, Salil Mohan

Theses

Heating rate effect and particle size effect on ignition temperature of Al powder were studied to collect data for development of a possible Al powder ignition model. Aluminum ignition is associated with a highly accelerated burn rate and high combustion enthalpy. A new ignition model, which can adequately interpret these conditions, is needed to develop better propulsion fuels, explosives and incendiaries that use Al as an additive. This experimental program was focused on preparing framework for characterization of ignition kinetics of Al powder by determining the ignition temperature for different, systematically varied, heating rates and particle size. The experimental setup …

Ground-Source Heat Pumps In Ireland: Heat Transfer Experimentation For The Design And Modelling Of A Sub-Slab Installation., Sarah O'Connell

Theses

Ground-source heat pump technology is currently undergoing rapid growth in Ireland. Three aspects of ground-source heat pumps have been studied in this thesis. The market expansion taking place in Ireland, heat transfer from the soil to the pipe of a ground- source heat pump collector, and the design of an innovative sub-slab ground-source heat pump system.

Initial investigations into the use of ground-source heat pumps in Ireland revealed surprising growth in the use of the technology. There have been approximately 1500 systems installed mainly since 2000. The ground-source heat pump market in Ireland has an estimated annual growth rate of …

Optimisation Of Heat Transfer And Fluid Flow In The Cooling Of Building Integrated Photovoltaic Facades., Eoin Patrick Hodge

Theses

The aim of this research was to explore the effects of mature and developing technologies from aeronautical industries such as impingement and film cooling, and electronic cooling techniques, in the setting up of different laminar and turbulent flow regimes on PV cooling duct heat transfer rates, with air flow as that brought about with natural buoyancy effects in a vertical building facade. The problem of efficiency losses in PV panels, due to overheating, is one of the factors restricting the development and use of this renewable power source. PV panels can experience very high temperatures, due to the heat input …

Magneto-Acoustic Emission Analysis Of Microstructural Change In Aisi 430 And Aisi 304 Stainless Steel, Denis O'Sullivan

Theses

Magneto-acoustic emission (MAE) is a relatively new non-destructive detection technique. Its working principle is based on Barkhausen discontinuities and magnetostriction within a ferromagnetic material that is subjected to a varying magnetic field. Magneto-acoustic emission (MAE) and magnetic Barkhausen noise (MBN) sensing techniques were developed and employed to characterise plastically deformed and heat-treated AISI 430 ferritic stainless steel and AISI 304 austenitic stainless steel samples. A new waveform measurement parameter for magneto-acoustic emission was developed called MAE (Absolute “energy”).

Both MAE and MBN were found to decrease with increasing plastic deformation of AISI 430. MAE (Absolute “energy”) and MBN (RMS) were …