Query: Millimeter-Scale, Micro-Electro- Mechanical Systems Gas Turbine Engines

Candidate papers:

abstract: The confluence of market demand for greatly improved compact power sources for portable electronics with the rapidly expanding capability of micromachining technology has made feasible the development of gas turbines in the millimeter size range. With airfoil spans measured in 100's of microns rather than meters, these microengines have about 1 millionth the airflow of large gas turbines and thus should produce about one millionth the power, 10 100 W. Based on semiconductor industry derived processing of materials such as silicon and silicon carbide to submicron accuracy, such devices are known as micro electro mechanical systems (MEMS) Current millimeter scale designs use centrifugal turbomachinery with pressure ratios in the range of 2:1 to 4:1 and turbine inlet temperatures of 1200 1600 K. The projected performance of these engines are on a par with gas turbines of the 1940s. The thermodynamics of MEMS gas turbines are the same as those for large engines but the mechanics differ due to scaling considerations and manufacturing constraints. The principal challenge is to arrive at a design which meets the thermodynamic and component functional requirements while staying within the realm of realizable micromachining technology. This paper reviews the state of the art of millimeter size gas turbine engines, including system design and integration, manufacturing, materials, component design, accessories, applications, and economics. It discusses the underlying technical issues, reviews current design approaches, and discusses future development and applications.
author_names: A H Epstein
title: Millimeter Scale, Micro Electro Mechanical Systems Gas Turbine Engines
year: 2004

abstract: The confluence of market demand for greatly improved compact power sources for portable electronics with the rapidly expanding capability of micromachining technology has made feasible the development of gas turbines in the millimeter size range. With airfoil spans measured in 100's of microns rather than meters, these "microengines" have about 1 millionth the air flow of large gas turbines and thus should produce about 1 millionth the power, 10 100 W. Based on semiconductor industry derived processing of materials such as silicon and silicon carbide to submicron accuracy, such devices are known as micro electro mechanical systems (MEMS) Current millimeter scale designs use centrifugal turbomachinery with pressure ratios in the range of 2:1 to 4:1 and turbine inlet temperatures of 1200 1600 K. The projected performance of these engines are on a par with gas turbines of the 1940's. The thermodynamics of MEMS gas turbines are the same as those for large engines but the mechanics differ due to scaling considerations and manufacturing constraints. The principal challenge is to arrive at a design which meets the thermodynamic and component functional requirements while staying within the realm of realizable micromachining technology. This paper reviews the state of the art of millimeter size gas turbine engines, including system design and integration, manufacturing, materials, component design, accessories, applications, and economics. It discusses the underlying technical issues, reviews current design approaches, and discusses future development and applications.
author_names: A H Epstein
title: Millimeter Scale, MEMS Gas Turbine Engines
year: 2003

abstract: The confluence of market demand for greatly improved compact power sources for portable electronics with the rapidly expanding capability of micromachining technology has made feasible the development of gas turbines in the millimeter size range. With airfoil spans measured in 100's of microns rather than meters, these "microengines" have about 1 millionth the air flow of large gas turbines and thus should produce about 1 millionth the power, 10 100 W. Based on semiconductor industry derived processing of materials such as silicon and silicon carbide to submicron accuracy, such devices are known as micro electro mechanical systems (MEMS) Current millimeter scale designs use centrifugal turbomachinery with pressure ratios in the range of 2:1 to 4:1 and turbine inlet temperatures of 1200 1600 K. The projected performance of these engines are on a par with gas turbines of the 1940's. The thermodynamics of MEMS gas turbines are the same as those for large engines but the mechanics differ due to scaling considerations and manufacturing constraints. The principal challenge is to arrive at a design which meets the thermodynamic and component functional requirements while staying within the realm of realizable micromachining technology. This paper reviews the state of the art of millimeter size gas turbine engines, including system design and integration, manufacturing, materials, component design, accessories, applications, and economics. It discusses the underlying technical issues, reviews current design approaches, and discusses future development and applications.
author_names: A H Epstein
title: GT 2003 38866 MILLIMETER SCALE MEMS GAS TURBINE ENGINES
year: 2003

abstract: In this study, it was attempted to estimate the flow characteristics in the vicinity of an engine inner wall from the instantaneous local heat fluxes measured using a micro electro mechanical systems sensor. As the sensor has three resistance temperature detectors with a size of 315 um fabricated on a circumference with a diameter of 900 um in rotational symmetry, it can measure local heat flux on the equivalent scale of the turbulence of in cylinder flow. The advective velocity and turbulent eddy scale were estimated from heat flux fluctuations using a cross correlation analysis, and these were compared with results of particle image velocimetry performed under motored operation conditions. As a result, it was found that the micro electro mechanical systems sensor has the potential to detect the gas side information such as the wall parallel flow velocity. Although further verification of the physical meanings of the estimated characteristics is necessary, the micro electro mechanical systems sensor will become a powerful tool for engine diagnostics.
author_names: Kazuhito Dejima

Osamu Nakabeppu
title: Attempt of estimating flow characteristics from wall heat fluxes measured using a three point micro electro mechanical systems sensor
year: 2020

abstract: There have been umpteen efforts in the past to convert an automotive turbocharger, consisting of a compressor and a turbine mounted on the same shaft, into a miniaturized gas turbine engine or micro gas turbine engine (mGTE) This paper presents the development of turbocharger based mGTE and its integration with an electrical power pack. This mGTE is used for validating the concept of electro mechanical interaction of these systems leading to electric power generation. The selection and sizing of the turbocharger center housing rotating assembly for the engine is carried out considering a wide range of industrial/consumer applications. All static parts including combustor have been designed and developed in view of the potential applications. The fuel air mixture when burnt in the combustor expands across the turbine and exits through the exhaust nozzle to produce thrust. The energy in the exhaust gas is utilized for running the power turbine which in turn is connected to an alternating current (AC) generator to produce electric power. A generator control unit that built in the alternator was used for voltage regulation. A control architecture has been designed to moderate the mGTE exhaust gas bypass valve in case of over speeding of the alternator. Also, a resistor based variable load bank was designed to demonstrate generator performance. The system can be made to run on multiple fuels (for example, bio gas, diesel or kerosene) with small changes to the combustion chamber. Few potential applications of the mGTE integrated power generator include decentralized power generation (microgrid) combined heating and cooling and laboratory platform for universities. The technology and system architecture developed for mGTE can be leveraged for applications such as Urban Air Mobility (UAM) electric propulsion.
author_names: K N Sudheendra

Kumar Sakinala

Davendar Kashireddy

Somashekhar M Maheswarappa Hosamane

Vadiraja Upadya

Deepak Kumar

Louis Cheng
title: Study of electro mechanical interaction in micro gas turbine engine generator system for more electric applications
venue: 2019 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)
year: 2019

abstract: Current commercial and heavy duty powertrains are geared towards emissions reduction. Energy recovery from exhaust gases has great potential, considering the mechanical work to be transferred back to the engine. For this purpose, an additional turbine can be implemented behind a turbocharger; this solution is called turbocompounding (TC) This paper considers the adaptation of turbine wheels and gearboxes of small turboshaft and turbojet engines into a two stage TC system for a six cylinder opposed piston engine that is currently under development. The initial conditions are presented in the first section, while a comparison between small turboshaft and turbojet engines and their components for TC is presented in the second section. Based on the comparative study, a total number of 7 turbojet and 8 turboshaft engines were considered for the TC unit.
author_names: Dariusz Kozak

Pawel Mazuro
title: Review of Small Gas Turbine Engines and Their Adaptation for Automotive Waste Heat Recovery Systems
year: 2020

abstract: Current trends in the aviation industry are aimed at upgrading avionics and replacing mechanical, hydraulic and pneumatic systems in favor of electrical systems. The article contains an analytical review of the starting devices of the gas turbine engine of an aircraft. The article analyzes the starting characteristics of an aircraft gas turbine engine, as well as the requirements for the design of electric starting devices of an aircraft engine. Options for building starter generator systems to increase the level of electrification of aircraft onboard equipment, within the framework of the concept of "more electric aircraft" are considered. Along with increasing the level of electrification, the problem of increasing the energy efficiency of existing electrical equipment of aircraft is acute. One of the criteria for the effective use of aviation equipment is the introduction of multifunctional onboard units and units. According to this criterion it is advisable to combine the starter and generator of the auxiliary power unit in one module.
author_names: Maksim A Zharkov

Regina Yu Sarakhanova
title: Analysis of Current State of the Starting Device for Aircraft Gas Turbine Engines
venue: 2020 International Ural Conference on Electrical Power Engineering (UralCon)
year: 2020

abstract: In the Arctic, submarines and equipment in the near future will carry out transport operations with overcoming ice fields underwater, as well as exploration, construction and operation of underwater objects. It is possible to use gas turbine plants in a single circuit version, which operate on hydrocarbon fuel, as closed ones for underwater equipment. The oxidizing agent is usually oxygen. The working fluid of closed gas turbine plants (CGTP) is a mixture of combustion products of hydrocarbon fuel and oxygen. Studies of the thermodynamic cycle characteristics of CGTP with oxygen as an oxidizer with various initial data have shown the possibility of operating micro gas turbine plants at nominal conditions with acceptable efficiency in engines with heat recovery. Higher efficiency indicators are obtained in CGTP with a turbocompressor utilizer (TCU) and a heat regenerator. However, power plants of underwater equipment are often operated at partial loads under various types of loads associated with their purpose. When determining characteristics in variable modes, the nominal parameters are the initial data. For SGTP with TCU and heat recovery (R) the efficiency is relatively 15 20% higher than for SGTP with R, and the specific power is 1.5 times higher. Investigation of the SGTP characteristics at partial loads is carried out under generator and screw loading, which are typical for underwater equipment. It has been established that SGTP with TCU and R at all loading modes have higher efficiency than SGTP with R. SGTP at partial loads with a screw type of loading are more economical than at variable generator loads. CGTP can produce mechanical and thermal energy, ensuring high energy efficiency of the plant in a submerged position.
author_names: Valerii T Matviienko

Vladimir A Ocheretianyi

Andrey V Dologlonyan
title: OPERATION AT VARIABLE MODES OF CLOSED MICRO GAS TURBINE PLANTS WITH OXIDIZER OXYGEN FOR UNDERWATER EQUIPMENT
year: 2020

abstract: The creation and exploitation of gas turbine engines (GTE) often involve two mutually exclusive tasks related to ensuring the highest reliability while achieving a good economic and environmental performance of the power plant. The value of the radial clearance between the blade tips of the compressor or turbine and the stator is a parameter that has a significant impact on the efficiency and safety of the GTE. However, the radial displacements that form tip clearances are only one of the components of the displacements made by GTE elements due to the action of power loads and thermal deformations during engines' operation. The impact of loads in conjunction with natural aging is also the reason for the wear of the GTE's structural elements (for example, bearing assemblies) and the loss of their mechanical strength. The article provides an overview of the methods and tools for monitoring the dangerous states of the GTE (blade tips clearances, impellers and shafts displacements, debris detecting in lubrication system) based on the single coil eddy current sensor, which remains operational at the temperatures above 1200 degC. The examples of practical application of the systems with such sensors in bench tests of the GTE are given.
author_names: Sergey Borovik

Yu N Sekisov
title: Single Coil Eddy Current Sensors and Their Application for Monitoring the Dangerous States of Gas Turbine Engines
venue: Sensors
year: 2020

abstract: The oil system of a gas turbine performs essential lubrication and thermal management functions, providing that the fluidic and tribological properties of the oil can meet functional requirements. New engine designs place increasing thermal and mechanical loads on the oil, and thus increase the risks of accelerated degradation potentially causing the oil properties to deviate from requirements. Presented with these risks, there is a potential business benefit for in situ oil condition knowledge to support oil system health management. Starting with the business needs elicited from stakeholders, a Quality Functional Deployment process is performed to derive sensing system requirements. Sensing principles are reviewed for their capability to assess tribological failure mechanisms, and this is related back to stakeholder requirements. A set of sensors were procured and a testing programme performed that exercises the sensors against different degradations of oil and the noise factors representative of service. These sensors are evaluated for their ability to provide oil condition information. The framework presented in this paper uses system engineering principles to derive a health system design and verification process. The results from verification are reported to aid in providing overarching system availability management.
author_names: Andrew R Mills

Shlomo Yaakov Gadelovits

Michael Leighton

Gurbuz Comak
title: Oil System Health Management for Aerospace Gas Turbine Engines
venue: 2019 IEEE Aerospace Conference
year: 2019