The Feasibility of Using an Air Turbine to Drive an Afterburner Fuel Pump

2003 ◽  
Author(s):  
N. E. Backus ◽  
K. W. Ramsden ◽  
M. K. Yates ◽  
P. Laskaridis ◽  
P. Pilidis
Keyword(s):  
Mass Flow ◽  
Engine Speed ◽  
Performance Data ◽  
Fuel Pump ◽  
Radial Turbine ◽  
Air Turbine ◽  
Fixed Proportion ◽  
Mass Flows ◽  
Electric Engine ◽  
Radial Turbines

Current fighter engine designs extract power to drive the afterburner fuel pump through the use of a gearbox. The presence of the gearbox only allows the fuel pump to operate at a fixed proportion of engine speed. In addition the fuel pump is continually rotating, although not pumping fuel, even when the afterburner is not engaged. This article investigates the feasibility of using an air turbine to drive the afterburner fuel pump in preparation for supporting an all-electric engine. Utilising performance data for a typical modern military engine, 1-dimensional design techniques were used to design several radial turbines to power the afterburner fuel pump. A choice of an axial or a radial air turbine is possible. Both were reviewed and it was determined that a radial turbine is optimum based on manufacturability and (theoretical) efficiency. Several design iterations were completed to determine the estimated weight and size based on various air off-take locations, mass flows, and rotational speeds. These iterations showed that increasing mass flow allows for lower rotational speeds and/or smaller diameter rotors, but with a corresponding increases in thrust penalties.

scholarly journals A Robust Adiabatic Model for a Quasi-Steady Prediction of Far-Off Non-Measured Performance in Vaneless Twin-Entry or Dual-Volute Radial Turbines

2020 ◽  
Vol 10 (6) ◽  
pp. 1955
Author(s):  
José Ramón Serrano ◽  
Francisco J. Arnau ◽  
Luis Miguel García-Cuevas ◽  
Vishnu Samala
Keyword(s):  
Mass Flow ◽  
Performance Parameters ◽  
Flow Conditions ◽  
Fitting Procedure ◽  
Radial Turbine ◽  
Novel Approach ◽  
Proposed Model ◽  
Double Entry ◽  
Radial Turbines ◽  
Fitting Parameters

The current investigation describes in detail a mass flow oriented model for extrapolation of reduced mass flow and adiabatic efficiency of double entry radial inflow turbines under any unequal and partial flow admission conditions. The model is based on a novel approach, which proposes assimilating double entry turbines to two variable geometry turbines (VGTs) using the mass flow ratio ( MFR ) between the two entries as the discriminating parameter. With such an innovative approach, the model can extrapolate performance parameters to non-measured MFR s, blade-to-jet speed ratios, and reduced speeds. Therefore, the model can be used in a quasi-steady method for predicting double entry turbines performance instantaneously. The model was validated against a dataset from two different double entry turbine types: a twin-entry symmetrical turbine and a dual-volute asymmetrical turbine. Both were tested under steady flow conditions. The proposed model showed accurate results and a coherent set of fitting parameters with physical meaning, as discussed in this paper. The obtained parameters showed very similar figures for the aforementioned turbine types, which allows concluding that they are an adequate set of values for initializing the fitting procedure of any type of double entry radial turbine.

scholarly journals Engine Performance of a Gardener Compression Ignition Engine using Rapeseed Methyl Esther

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Hamisu A Dandajeh ◽  
Talib O Ahmadu
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Air Mass

This paper presents an experimental investigation on the influence of engine speed on the combustion characteristics of a Gardener compression ignition engine fueled with rapeseed methyl esther (RME). The engine has a maximum power of 14.4 kW and maximum speed of 1500 rpm. The experiment was carried out at speeds of 750 and 1250 rpm under loads of 4, 8, 12, 16 and 18 kg. Variations of cylinder pressure with crank angle degrees and cylinder volume have been examined. It was found that RME demonstrated short ignition delay primarily due to its high cetane number and leaner fuel properties (equivalence ratio (φ) = 0.22 at 4kg). An increase in thermal efficiency but decrease in volumetric efficiency was recorded due to increased brake loads. Variations in fuel mass flow rate, air mass flow rate, exhaust gas temperatures and equivalence ratio with respect to brake mean effective pressure at engine speeds of 750 and 1250 rpm were also demonstrated in this paper. Higher engine speed of 1250 rpm resulted in higher fuel and air mass flow rates, exhaust temperature, brake power and equivalent ratio but lower volumetric efficiency. Keywords— combustion characteristics, engine performance, engine speed, rapeseed methyl Esther

scholarly journals Improvement of Pump Performance at Off-Design Conditions

1985 ◽  
Author(s):  
J. Paulon ◽  
C. Fradin ◽  
J. Poulain
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Mass Flow ◽  
Flow Characteristic ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Pump Performance ◽  
Wide Range ◽  
Mass Flows ◽  
Design Value

Industrial pumps are generally used in a wide range of operating conditions from almost zero mass flow to mass flows larger than the design value. It has been often noted that the head-mass flow characteristic, at constant speed, presents a negative bump as the mass flow is somewhat smaller than the design mass flows. Flow and mechanical instabilities appear, which are unsafe for the facility. An experimental study has been undertaken in order to analyze and if possible to palliate these difficulties. A detailed flow analyzis has shown strong three dimensional effects and flow separations. From this better knowledge of the flow field, a particular device was designed and a strong attenuation of the negative bump was obtained.

Condensation in Radial Turbines—Part I: Mathematical Modeling

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Sebastian Schuster ◽  
Dieter Brillert ◽  
Friedrich-Karl Benra
Keyword(s):  
Waste Heat ◽  
Saturation Temperature ◽  
Steam Temperature ◽  
Radial Turbine ◽  
Liquid Film Flow ◽  
Quantitative Analyses ◽  
Computational Fluid Dynamics Cfd ◽  
Droplet Liquid ◽  
Radial Turbines ◽  
Turbine Impeller

In this two-part paper, the investigation of condensation in the impeller of radial turbines is discussed. In Paper I, a solution strategy for the investigation of condensation in radial turbines using computational fluid dynamics (CFD) methods is presented. In Paper II, the investigation methodology is applied to a radial turbine type series that is used for waste heat recovery. First, the basic CFD approach for the calculation of the gas-droplet-liquid-film flow is introduced. Thereafter, the equations connecting the subparts are explained and a validation of the models is performed. Finally, in Paper I, condensation phenomena for a selected radial turbine impeller are discussed on a qualitative basis. Paper II continues with a detailed quantitative analyses. The aim of Paper I is to explain the models that are necessary to study condensation in radial turbines and to validate the implementation against available experiments conducted on isolated effects. This study aims to develop a procedure that is applicable for investigation of condensation in radial turbines. Furthermore, the main processes occurring in a radial turbine once the steam temperature is below the saturation temperature are explained and analyzed.

Performance Analysis of an Indirect Fired Air Turbine Cogeneration System

1985 ◽  
Author(s):  
Francis F. Huang ◽  
Fokion Egolfopoulos
Keyword(s):  
Thermal Energy ◽  
Performance Data ◽  
Utilization Efficiency ◽  
Energy Ratio ◽  
Design Stage ◽  
Second Law ◽  
Inlet Temperature ◽  
Fuel Utilization ◽  
Air Turbine ◽  
Cogeneration System

A thermodynamic study of an indirect fired air turbine cogeneration system for the production of electricity and process steam has been made. Performance data showing the effect of compressor compression ratio and turbine inlet temperature on fuel utilization efficiency (first law efficiency), electrical to thermal energy ratio (power to heat ratio) and second law efficiency (exergetic efficiency) have been generated. Although fuel utilization efficiency and electrical to thermal energy ratio data do provide some useful information, it is the second law efficiency that provides the optimal design conditions. The performance data contained in this study should be useful to the decision-makers in the selection of optimal parameters at the system design stage of an indirect fired air turbine cogeneration system.

scholarly journals A new approach in CHP steam turbines thermodynamic cycles computations

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 399-407 ◽  
Author(s):  
Vojin Grkovic ◽  
Dragoljub Zivkovic ◽  
Milana Gutesa
Keyword(s):  
Electric Power ◽  
Mass Flow ◽  
Direct Calculation ◽  
Energy System ◽  
Combined Heat And Power ◽  
Load Parameter ◽  
Steam Turbines ◽  
New Approach ◽  
Thermodynamic Cycles ◽  
Mass Flows

This paper presents a new approach in mathematical modeling of thermodynamic cycles and electric power of utility district-heating and cogeneration steam turbines. The approach is based on the application of the dimensionless mass flows, which describe the thermodynamic cycle of a combined heat and power steam turbine. The mass flows are calculated relative to the mass flow to low pressure turbine. The procedure introduces the extraction mass flow load parameter ?h which clearly indicates the energy transformation process, as well as the cogeneration turbine design features, but also its fitness for the electrical energy system requirements. The presented approach allows fast computations, as well as direct calculation of the selected energy efficiency indicators. The approach is exemplified with the calculation results of the district heat power to electric power ratio, as well as the cycle efficiency, versus ?h. The influence of ?h on the conformity of a combined heat and power turbine to the grid requirements is also analyzed and discussed.

Development of the Electric Fuel System for the More Electric Engine

2014 ◽  
Author(s):  
Noriko Morioka ◽  
Hitoshi Oyori ◽  
Yukinori Gonda ◽  
Kenji Takamiya ◽  
Yasuhiko Yamamoto
Keyword(s):  
Electric Motor ◽  
Aircraft Engine ◽  
Fuel System ◽  
Motor Speed ◽  
Pump System ◽  
Fuel Pump ◽  
Fuel Flow ◽  
Set Up ◽  
Electric Fuel Pump ◽  
Electric Engine

This paper describes the experimental rig test result of the electric motor-driven fuel pump system for the MEE (More Electric Engine). The MEE is an aircraft engine system concept, which replaces conventional mechanical/hydraulic driven components with electric motor-driven components. Various MEE approaches have been studied since the early 2000s and one of its key concepts is an electric motor-driven fuel pump [1–4]. The authors commenced a feasibility study of the electric motor-driven gear pump system for what was assumed to be a small-sized turbofan engine. The concept study and system design were conducted, whereupon technical issues for the electric fuel pump system, which both supplies and meters fuel via the motor speed control, were clarified [5, 6]. Since one of the key issues is fuel-metering accuracy, the electric fuel system, including a flow feedback closed-loop control, was designed to ensure accurate fuel-flow metering for aircraft engine applications. To verify the rig system, an experimental model of the electric fuel pump system is assumed for a small-sized turbofan engine. The hardware of the motor-driven fuel pump and flow measurement mechanism, including an FPV (Fuel-Pressurizing Valve) and orifice, were designed, manufactured and fabricated and a differential pressure sensor for flow feedback was selected. Other equipment was also prepared, including a motor controller, power source and measurement devices, and the entire rig set-up was constructed. A bench test using the rig test set-up was conducted to verify the fuel-metering accuracy, response and system stability. Data, including the static performance and frequency response, were obtained for the electric motor, motor-driven fuel pump and entire fuel system respectively. The rig test results indicate the feasibility of the system, which will provide an accurate engine fuel flow (Wf) measurement and frequency response required for actual engine operation, via an electric motor speed control and fuel-flow feedback system, as proposed in the MEE electric fuel system.

The dynamics and impacts of the December 2017 catastrophic mass flow Villa Santa Lucia, Chile

2020 ◽  
Author(s):  
Holly Chubb ◽  
Andrew Russell ◽  
Alejandro Dussaillant ◽  
Stuart Dunning
Keyword(s):  
Debris Flow ◽  
Mass Flow ◽  
Southern Oscillation ◽  
Significant Risk ◽  
Flow Path ◽  
Intense Rainfall ◽  
Enso Events ◽  
The Future ◽  
Mass Flows ◽  
Insight Into

<p>Landslides and mass flows are dynamic processes that involve the movement of rock, debris and earth down a slope. As a result of the 2017 catastrophic mass flow, these processes have been further established as a significant risk to the population of Chile, and further afield. Through field site investigations, it is possible to develop a greater insight into the mechanisms and conditions that influence the dynamics of these phenomena.</p><p>On Saturday 16 December 2017, a catastrophic debris flow (aluvión) partially destroyed the village of Villa Santa Lucía and a 5 km long reach of the Panamerican Highway resulting in 22 fatalities. The apparent trigger was an intense rainfall event of 124 mm in 24h associated with an elevated 0˚C isotherm (1600 m.a.s.l.) that led to the failure of 5.5 - 6.8x10<sup>6</sup>m<sup>3 </sup> mountainside in the uppermost catchment of Rio Burritos near the SE end of the Cordón Yelcho Glacier. The landslide transformed rapidly into a highly mobile debris flow as it entrained water from the Rio Burritos river and glacier ice from the Cordón Yelcho.</p><p>This study characterises the geomorphological impacts and dynamics of the 2017 mass flow. Post-event DEMs, aerial photos and satellite imagery provided the basis for geomorphological mapping and terrain analysis. Fieldwork in January 2019 allowed sampling of mass flow deposits, logging of sedimentary sections and dGPS surveys.</p><p>Both erosion and deposition occurred over the Villa Santa Lucía flow path. Erosion occurred more frequently in the first 7.9km of the flow path due to high slope angles and presence of the Rio Burritos that channelised flow. A high proportion of coarse particles in the flow enhanced basal scouring and erosion of the valley sides, resulting in significant flow bulking. A total of 7.6x10<sup>6</sup>m<sup>3</sup> – 7.7x10<sup>6</sup>m<sup>3 </sup> of material was deposited across the latter 6.3km of the flow path.</p><p>Sediment sample analysis showed that the flow began as cohesive and viscous in nature in spite of a lack of clay particles and high proportions of sands and gravels. The addition of water from the Rio Burritos reduced the viscosity of the flow as the flow propagated downstream. This resulted in enhanced lobe spreading and particle interactions in the depositional zone. In spite of this water entrainment, the flow remained both sediment and debris rich over its duration.</p><p>Catastrophic mass flows like the event at Villa Santa Lucía are likely to become more common around the world in the future as intense rainfall events become more frequent due to the dominance of El Nino Southern Oscillation (ENSO) events. By studying recent catastrophic mass flow events, an insight into the relationship between mass flow triggers and flow composition will be developed. This will allow for greater understanding of how these influence mass flow behaviours. As a result, it may then be possible to predict the rheology and routes of future flows. These predictions have the ability to be used to protect communities from such events in the future.</p>

Paper 23: An Experimental Investigation of Non-Steady Flow in a Radial Gas Turbine

1965 ◽  
Vol 180 (10) ◽  
pp. 74-85 ◽  
Author(s):  
R. S. Benson ◽  
K. H. Scrimshaw
Keyword(s):  
Steady Flow ◽  
Mass Flow ◽  
Pulse Generator ◽  
Flow Analysis ◽  
Pulse Frequency ◽  
Exhaust Pipe ◽  
Transient Pressure ◽  
Radial Turbine ◽  
Admission Data ◽  
Partial Admission

Comprehensive steady and non-steady flow tests on a small radial turbine turbo-charger are given. Steady flow tests included both full admission and partial admission over the whole speed and pressure range from zero flow to maximum flow. Non-steady flow tests were carried out over a pulse frequency range from 30 to 70 pulses/s and turbine speeds from 30 000 to 60 000 rev/min with the turbine coupled to the exhaust system of a six-cylinder pulse generator under partial admission conditions. Extensive transient pressure and temperature measurements were taken upstream and downstream (pressure only) of the turbine. The total mass flow and power were also measured. A quasi-steady flow analysis was carried out using the steady flow test data. The tests results showed that for a six-cylinder exhaust pipe configuration, with two exhaust pipes entering separate nozzle segments in the radial turbine, the quasi-steady flow analysis using partial admission data grossly underestimated the mass flow and power output of the turbine. Using full admission data the ratio of measurement mass flow and horsepower to the calculated mass flow and horsepower was nearly always greater than unity. Furthermore, the average turbine efficiency was greater under non-steady flow than under steady flow. The magnitude of the recorded effects was dependent on the pulse frequency and turbine speed.

scholarly journals Swirl Generation and Recirculation Using Radial Swirl Vanes

1993 ◽  
Author(s):  
John L. Halpin
Keyword(s):  
Finite Element ◽  
Computer Modeling ◽  
Mass Flow ◽  
Flow Fields ◽  
Swirl Number ◽  
Counter Rotation ◽  
Inlet Swirl ◽  
Mass Flows ◽  
Flow Effects ◽  
Cup Design

The concept of the Swirl Number and its effect on recirculation is reviewed and problems with it are identified. Swirl generation through the use of radial inlet swirl vanes is then studied. The effect of vane and swirl cup design on recirculation is then evaluated using finite element computer modeling and verified using tufting tests. Vane geometry, combustor dome geometry, co- vs. counter-rotation and mass flow effects are all evaluated. It is shown that co- and counter-rotation generate very similar flow fields and recirculated mass flows. An approach for calculating swirl numbers in multiple swirler designs is proposed.

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