Study of Thermofluid Dynamics of an Ultra-Micro Scale Gas "Turbine"
type: CreativeWork
description: This thesis aims to study the thermofluid dynamic behaviour through a component of an ultra-micro scale gas turbine (UMGT), the turbine. Here an experimental investigation is firstly conducted to serve as a basis for numerical validation and to prove the feasibility of a 3 dimensional (3D) UMGT scale radial inflow turbine. A numerical investigation of the experimental turbine is then carried out, where the effects of heat loss, which are enhanced at small (and therefore UMGT) scales, on the turbine performance are studied through adiabatic and isothermal boundary conditions. Lastly, four different turbines from microscale gas turbines (MGT) (100kW and 20kW) to UMGT scales (1kW and 250W) that are geometricallyand dynamically similar, are numerically investigated. The performance of the turbine and thermofluid dynamic losses due to lowered Reynolds ( ) numbers when scaling down to UMGT scale are quantified.The experimental investigation successfully tested the UMGT turbine, with a 20mm rotor diameter, 3Dprinted from Ti64. A maximum electrical power of 5.4W was attained at a rotational speed of 57,000 rpm for the highest temperature and flow rate of 80°C and 150 standard litres per minute. Here an overall efficiency as large as 28% was attained, and has therefore successfully proven the feasibility of a UMGT turbine. Experimental findings however, were limited, as the turbine was not tested at design point due to component and material inabilities. The experimental turbine also served as a basis to validate the numerical procedure, and here a difference of less than 10 and 2% was attained for the turbine power and pressure ratio plots, as a function of the rotational speed. A numerical investigation on the experimental turbine showed the effects of heat loss reduced the performance of the turbine by 2% from the adiabatic wall boundary condition, where an efficiency of 76% was attained, at the design specific speed ( ) of 0.51. The drop in efficiency is not as significa…
abstract: This thesis aims to study the thermofluid dynamic behaviour through a component of an ultra-micro scale gas turbine (UMGT), the turbine. Here an experimental investigation is firstly conducted to serve as a basis for numerical validation and to prove the feasibility of a 3 dimensional (3D) UMGT scale radial inflow turbine. A numerical investigation of the experimental turbine is then carried out, where the effects of heat loss, which are enhanced at small (and therefore UMGT) scales, on the turbine performance are studied through adiabatic and isothermal boundary conditions. Lastly, four different turbines from microscale gas turbines (MGT) (100kW and 20kW) to UMGT scales (1kW and 250W) that are geometricallyand dynamically similar, are numerically investigated. The performance of the turbine and thermofluid dynamic losses due to lowered Reynolds ( ) numbers when scaling down to UMGT scale are quantified.The experimental investigation successfully tested the UMGT turbine, with a 20mm rotor diameter, 3Dprinted from Ti64. A maximum electrical power of 5.4W was attained at a rotational speed of 57,000 rpm for the highest temperature and flow rate of 80°C and 150 standard litres per minute. Here an overall efficiency as large as 28% was attained, and has therefore successfully proven the feasibility of a UMGT turbine. Experimental findings however, were limited, as the turbine was not tested at design point due to component and material inabilities. The experimental turbine also served as a basis to validate the numerical procedure, and here a difference of less than 10 and 2% was attained for the turbine power and pressure ratio plots, as a function of the rotational speed. A numerical investigation on the experimental turbine showed the effects of heat loss reduced the performance of the turbine by 2% from the adiabatic wall boundary condition, where an efficiency of 76% was attained, at the design specific speed ( ) of 0.51. The drop in efficiency is not as significa…
author: D'Souza, Rohann
license: https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm
date published: 2019
date modified: 2026-07-24T01:07:07Z
provider: University of Auckland
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: ResearchSpace@Auckland

PropertyValue
property ID: Handle
value: https://hdl.handle.net/2292/49346