scholarly journals Integration of Helicopter Annular Combustion Chamber Rig in Propulsion Systems Course for Graduate Students

2018 ◽  
Author(s):  
I. Al-Asmi ◽  
A. Vandel ◽  
G. Cabot ◽  
F. Grisch ◽  
V. Moureau ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Systems Engineering ◽  
Engineering Students ◽  
Practical Experience ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Pollutant Emissions ◽  
Test Facility ◽  
Propulsion Systems ◽  
Flow Rates

The integration of graduate research in the training of engineering students has demonstrated a significant increase in learning efficiency, by giving them a practical experience with real industrial issues. The department of Energy and Propulsion of National Institute of Applied Sciences in Normandy, a French Engineering School, continues to implement the latest fully instrumented facilities in their field to initiate the students to inquiry-based education courses. In this type of education, they are carrying out a series of tests, learning how to handle equipment, control and monitor tests, extract results and ultimately analyze and present them in technical reports. This paper addresses how the Helicopter Annular Combustion Chamber test facility has been integrated in the Propulsion systems engineering course sequence. The Annular Combustion Chamber kindly provided by SAFRAN Helicopter Engines was progressively incorporated and instrumented in a dedicated test facility by the students themselves along the last 8 years. Now, this laboratory practical work offers the students the possibility to interactively learn about the operation of a combustion chamber inside a helicopter engine at various air/fuel flow rates. Students learn how to determine the limits of ignition/non-extinction as a function of the entry air-flow rate. In addition, this facility is equipped with high-level instrumentation that allows to measure the different flow rates, pressure, temperature inside and outside the annular chamber, and the pollutant emissions at the exit. Results provided by students help to build a comprehensive knowledge base of combustion phenomena inside a turbojet engine. It is to be mentioned that this educational facility is unique in its category, from the point of view of results accuracy, instrumentation level and realistic operating conditions.

Implementation of a Remote Pump Laboratory Exercise in the Training of Engineering Students

2012 ◽  
Author(s):  
Lucio Monaco ◽  
Damian M. Vogt ◽  
Torsten H. Fransson
Keyword(s):  
Test Data ◽  
Engineering Students ◽  
Practical Experience ◽  
Department Of Energy ◽  
Test Facility ◽  
Parallel Operation ◽  
Web Based ◽  
Laboratory Exercise ◽  
Email Address ◽  
Mass Flow Rates

The use of laboratory exercises in the training of engineering students is of paramount importance to give the students the possibility to gain practical experience on real hardware and on real test data. Recent trends in the education of engineers at the Department of Energy Technology at KTH go towards an increasing share of distant-based education, which is put in place to educate students at different geographic locations, not only locally (such as for example with engineers in industry) but also internationally (i.e. with students in different countries). In order to provide the possibility to follow a course at a distance without compromising on learning objectives and learning quality, a number of remotely operated laboratory exercises have been developed and implemented in the engineering curriculum at the department. Among these, to mention the work carried out by Navarathna et al. [11] on a remotely operated linear cascade test facility. The present laboratory exercise is integrated in a course on turbomachinery and gives the students the possibility to interactively learn about the operation of pumps at various speeds, various mass flow rates, parallel operation and serial operation. Students access the laboratory exercise using a web-based interface, perform measurements and finally have test data sent to an initially specified email address for further analysis.

Prediction of gaseous pollutant emissions from a spark-ignition direct-injection engine with gas-exchange simulation

2021 ◽  
pp. 146808742110050
Author(s):  
Stefania Esposito ◽  
Lutz Diekhoff ◽  
Stefan Pischinger
Keyword(s):  
Gas Exchange ◽  
Combustion Chamber ◽  
Direct Injection ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Operating Parameters ◽  
Gaseous Pollutant ◽  
Fuel Ratio ◽  
No Emissions

With the further tightening of emission regulations and the introduction of real driving emission tests (RDE), the simulative prediction of emissions is becoming increasingly important for the development of future low-emission internal combustion engines. In this context, gas-exchange simulation can be used as a powerful tool for the evaluation of new design concepts. However, the simplified description of the combustion chamber can make the prediction of complex in-cylinder phenomena like emission formation quite challenging. The present work focuses on the prediction of gaseous pollutants from a spark-ignition (SI) direct injection (DI) engine with 1D–0D gas-exchange simulations. The accuracy of the simulative prediction regarding gaseous pollutant emissions is assessed based on the comparison with measurement data obtained with a research single cylinder engine (SCE). Multiple variations of engine operating parameters – for example, load, speed, air-to-fuel ratio, valve timing – are taken into account to verify the predictivity of the simulation toward changing engine operating conditions. Regarding the unburned hydrocarbon (HC) emissions, phenomenological models are used to estimate the contribution of the piston top-land crevice as well as flame wall-quenching and oil-film fuel adsorption-desorption mechanisms. Regarding CO and NO emissions, multiple approaches to describe the burned zone kinetics in combination with a two-zone 0D combustion chamber model are evaluated. In particular, calculations with reduced reaction kinetics are compared with simplified kinetic descriptions. At engine warm operation, the HC models show an accuracy mainly within 20%. The predictions for the NO emissions follow the trend of the measurements with changing engine operating parameters and all modeled results are mainly within ±20%. Regarding CO emissions, the simplified kinetic models are not capable to predict CO at stoichiometric conditions with errors below 30%. With the usage of a reduced kinetic mechanism, a better prediction capability of CO at stoichiometric air-to-fuel ratio could be achieved.

Investigation of Flame Stabilization in a High-Pressure Multi-Jet Combustor by Laser Measurement Techniques

2014 ◽  
Author(s):  
Oliver Lammel ◽  
Tim Rödiger ◽  
Michael Stöhr ◽  
Holger Ax ◽  
Peter Kutne ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Recirculation Zone ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Single Shot ◽  
Optical Access

In this contribution, comprehensive optical and laser based measurements in a generic multi-jet combustor at gas turbine relevant conditions are presented. The flame position and shape, flow field, temperatures and species concentrations of turbulent premixed natural gas and hydrogen flames were investigated in a high-pressure test rig with optical access. The needs of modern highly efficient gas turbine combustion systems, i.e., fuel flexibility, load flexibility with increased part load capability, and high turbine inlet temperatures, have to be addressed by novel or improved burner concepts. One promising design is the enhanced FLOX® burner, which can achieve low pollutant emissions in a very wide range of operating conditions. In principle, this kind of gas turbine combustor consists of several nozzles without swirl, which discharge axial high momentum jets through orifices arranged on a circle. The geometry provides a pronounced inner recirculation zone in the combustion chamber. Flame stabilization takes place in a shear layer around the jet flow, where fresh gas is mixed with hot exhaust gas. Flashback resistance is obtained through the absence of low velocity zones, which favors this concept for multi-fuel applications, e.g. fuels with medium to high hydrogen content. The understanding of flame stabilization mechanisms of jet flames for different fuels is the key to identify and control the main parameters in the design process of combustors based on an enhanced FLOX® burner concept. Both experimental analysis and numerical simulations can contribute and complement each other in this task. They need a detailed and relevant data base, with well-known boundary conditions. For this purpose, a high-pressure burner assembly was designed with a generic 3-nozzle combustor in a rectangular combustion chamber with optical access. The nozzles are linearly arranged in z direction to allow for jet-jet interaction of the middle jet. This line is off-centered in y direction to develop a distinct recirculation zone. This arrangement approximates a sector of a full FLOX® gas turbine burner. The experiments were conducted at a pressure of 8 bar with preheated and premixed natural gas/air and hydrogen/air flows and jet velocities of 120 m/s. For the visualization of the flame, OH* chemiluminescence imaging was performed. 1D laser Raman scattering was applied and evaluated on an average and single shot basis in order to simultaneously and quantitatively determine the major species concentrations, the mixture fraction and the temperature. Flow velocities were measured using particle image velocimetry at different section planes through the combustion chamber.

Analysis of the Self-Excited Dynamics of a Heavy-Duty Annular Combustion Chamber by Large-Eddy Simulation

2019 ◽  
Author(s):  
Vittorio Michelassi ◽  
Roberto Meloni ◽  
Giovanni Riccio ◽  
Gianni Ceccherini
Keyword(s):  
Combustion Chamber ◽  
Operating Conditions ◽  
Test Facility ◽  
Heavy Duty ◽  
Mean Flow ◽  
Combustion Dynamics ◽  
Eddy Simulation ◽  
Stable Operating ◽  
Large Eddy ◽  
Accuracy Data

Abstract This paper discusses the use of LES to predict the performance of an annular combustion chamber in stable operating conditions and in presence of self-exited dynamics. The availability of high-accuracy data taken in a full-scale combustion test facility allowed an extensive validation of the prediction capability. The analysis focuses on a small size heavy duty annular gas turbine whose size allows to test and compute the entire 360° combustion chamber. The comparison with measurements confirms that, if the correct operating conditions are implemented, LES is capable to discern between stable and unstable operating conditions, as well as predict several other engineering relevant parameters, although the model is sometime affected by a limited shift in frequency. The post processing of LES results in presence of combustion dynamics is not a trivial task. Here the results of the simulations have been post-processed by means of a triple decomposition method to determine a mean flow, a deterministic unsteady flow at the main instability frequency and a turbulent stochastic flow. Such decomposition indicated the instability triggering mechanism together with the cross-talk mechanism between different components. This approach is currently used for design phase, while further validation is on-going to include different geometries and operating conditions with the goal of reducing both risks and number of tests.

scholarly journals Maintaining a Technology-Neutral Approach to Hydrogen Production Process Development Through Conceptual Design of the Next Generation Nuclear Plant

2008 ◽  
Author(s):  
Michael W. Patterson ◽  
Charles V. Park
Keyword(s):  
Hydrogen Production ◽  
Conceptual Design ◽  
Systems Engineering ◽  
Process Development ◽  
Nuclear Plant ◽  
Economic Feasibility ◽  
Department Of Energy ◽  
Test Facility ◽  
Next Generation ◽  
Process Technology

The Energy Policy Act of 2005 (EPAct) charges the Department of Energy (DOE) with developing and demonstrating the technical and economic feasibility of using high temperature gas-cooled reactor (HTGR) technology for the production of electricity and/or hydrogen. The design, construction and demonstration of this technology in an HTGR proto-type reactor are termed the Next Generation Nuclear Plant (NGNP) Project. Currently, parallel development of three hydrogen production processes will continue until a single process technology is recommended for final demonstration in the NGNP — a technology neutral approach. This analysis compares the technology neutral approach to acceleration of the hydrogen process downselection at the completion of the NGNP conceptual design to improve integration of the hydrogen process development and NGNP Project schedule. The accelerated schedule activities are based on completing evaluations and achieving technology readiness levels (TRLs) identified in NGNP systems engineering and technology roadmaps. The cost impact of accelerating the schedule and risk reduction strategies was also evaluated. The NGNP Project intends to design and construct a component test facility (CTF) to support testing and demonstration of HTGR technologies, including those for hydrogen production. The demonstrations will support scheduled design and licensing activities, leading to subsequent construction and operation of the NGNP. Demonstrations in the CTF are expected to start about two years earlier than similarly scaled hydrogen demonstrations planned in the technology neutral baseline. The schedule evaluation assumed that hydrogen process testing would be performed in the CTF and synchronized the progression of hydrogen process development with CTF availability.

Falling-Film Absorption Around Microchannel Tube Banks

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Ananda Krishna Nagavarapu ◽  
Srinivas Garimella
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Water Solution ◽  
Small Diameter ◽  
Operating Conditions ◽  
Test Facility ◽  
Vapor Flow ◽  
Falling Film ◽  
Flow Rates ◽  
Wide Range

An experimental investigation of heat and mass transfer in a falling-film absorber with microchannel tube arrays was conducted. Liquid ammonia–water solution flows in a falling-film mode around an array of small diameter coolant tubes, while vapor flows upward through the tube array counter-current to the falling film. This absorber was installed in a test facility consisting of all components of a functional single-effect absorption chiller, including a desorber, rectifier, condenser, evaporator, solution heat exchanger, and refrigerant precooler, to obtain realistic operating conditions at the absorber and to account for the influence of the other components in the system. Unlike studies in the literature on bench-top, single-component, single-pressure test stands, here the experiments were conducted on the absorber at vapor, solution, and coupling fluid conditions representative of space-conditioning systems in the heating and cooling modes. Absorption measurements were taken over a wide range of solution flow rates, concentrations, and coupling fluid temperatures, which simulated operation of thermally activated absorption systems at different cooling capacities and ambient conditions. These measurements are used to interpret the effects of solution and vapor flow rates, concentrations, and coupling fluid conditions on the respective heat and mass transfer coefficients.

LEADERSHIP AND COLLABORATION IN PROJECT MANAGEMENT EDUCATION: A CASE STUDY

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Silvia Mazzetto
Keyword(s):  
Higher Education ◽  
Project Management ◽  
Systems Engineering ◽  
Engineering Students ◽  
Multidisciplinary Approach ◽  
Practical Experience ◽  
University Education ◽  
Apparent Lack ◽  
Multidisciplinary Collaboration ◽  
Theoretical Approaches

This paper discusses about the importance of practical experience and multidisciplinary collaboration in project management success and the apparent lack of emphasis placed on this within the context of university education. It introduces a multidisciplinary approach currently being implemented in the College of Engineering in Qatar University between the departments of Architecture and Urban Planning and Industrial and Systems Engineering. The research items cover specific areas of collaboration and leadership in project management and the collected data was then analyzed to compare Architecture and Engineering students in their approach to the multidisciplinary project and in the proper application of managerial tools for planning scope, time, cost and risk managements through integration, technology and communication. The paper provides strategies of effective practices applied for embedding enterprise and employability in higher education, in respect to the specific project experiences that are mandatory for each project manager. The students’ outcomes demonstrate their ability to recognize the dialectic relationship between project management and the multidisciplinary approach to recognize the diversity of roles, needs, values, tools, as they relate their experience to the current environment for project management in Qatar. In other words, the question is: can the multidisciplinary collaboration, applied in higher education, enhance the interaction between theory and practical experience in a field mainly dominated by the theoretical approaches of different disciplines?

scholarly journals Analysis of the Michaelis-Menten mechanism in an immobilised enzyme reactor

2005 ◽  
Vol 47 (2) ◽  
pp. 173-184 ◽  
Author(s):  
M. I. Nelson ◽  
X. D. Chen ◽  
M. J. Sexton
Keyword(s):  
Flow Reactor ◽  
Reaction Vessel ◽  
High Flow ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Low Flow ◽  
Enzyme Reactor ◽  
Flow Rates ◽  
Periodic Behaviour ◽  
Enzyme Species

AbstractWe investigate the behaviour of a reaction described by Michaelis-Menten kinetics in an immobilised enzyme reactor (IER). The IER is treated as a well-stirred flow reactor, with the restriction that bounded and unbounded enzyme species are constrained to remain within the reaction vessel. Our aim is to identify the best operating conditions for the reactor.The cases in which an iminobilised enzyme reactor is used to either reduce pollutant emissions or to synthesise a product are considered. For the former we deduce that the reactor should be operated using low flow rates whereas for the latter high flow rates are optimal. It is also shown that periodic behaviour is impossible.

Verified Accurate Performance Simulation Model of Direct Thermosyphon Solar Energy Water Heaters

1988 ◽  
Vol 110 (4) ◽  
pp. 282-292 ◽  
Author(s):  
P. A. Hobson ◽  
B. Norton
Keyword(s):  
Solar Energy ◽  
Operating Conditions ◽  
Test Facility ◽  
Flow Rates ◽  
Water Heaters ◽  
Accurate Performance ◽  
Small Flow ◽  
Energy Equations ◽  
Capacitance Effects ◽  
Friction Factor Correlation

A detailed analysis of the heat transfers and fluid flows within direct thermosyphonic solar energy water heaters has been undertaken. The collector energy equations were cast in a two-dimensional form in order that the heat transfer and thermal capacitance effects can be simulated accurately at the small flow rates encountered commonly in these buoyancy-driven systems. The use of an appropriate nonisothermal friction factor correlation when calculating energy losses in the collector’s riser pipes, produced predicted flow rates which were corroborated to within 2 percent by the values measured under steady flow conditions. For the laminar flow rates and the store configuration investigated, relaxation of the thermocline was shown to be dominated by axial conduction in the store walls. An indoor test facility, monitored and controlled by a microcomputer, enabled “real” operating conditions to be simulated. The predicted responses of the system to identical conditions showed good agreement with the corresponding experimental observations, the predicted heat delivery being within 2.8 percent of that measured.

Analysis of the Self-Excited Dynamics of a Heavy-Duty Annular Combustion Chamber by Large-Eddy Simulation

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Roberto Meloni ◽  
Gianni Ceccherini ◽  
Vittorio Michelassi ◽  
Giovanni Riccio
Keyword(s):  
Large Eddy Simulation ◽  
Combustion Chamber ◽  
Operating Conditions ◽  
Test Facility ◽  
Heavy Duty ◽  
Mean Flow ◽  
Combustion Dynamics ◽  
Eddy Simulation ◽  
Stable Operating ◽  
Large Eddy

Abstract This paper discusses the use of large eddy simulation (LES) to predict the performance of an annular combustion chamber in stable operating conditions and in the presence of self-exited dynamics. The availability of high-accuracy data taken in a full-scale combustion test facility allowed an extensive validation of the prediction capability. The analysis focuses on a small size heavy duty annular gas turbine whose size allows to test and compute the entire 360 deg combustion chamber. The comparison with measurements confirms that, if the correct operating conditions are implemented, LES is capable to discern between stable and unstable operating conditions, as well as predict several other engineering relevant parameters, although the model is sometime affected by a limited shift in frequency.The post processing of LES results in presence of combustion dynamics is not a trivial task. Here, the results of the simulations have been postprocessed by means of a triple decomposition method to determine a mean flow, a deterministic unsteady flow at the main instability frequency, and a turbulent stochastic flow. Such decomposition indicated the instability triggering mechanism together with the cross-talk mechanism between different components. This approach is currently used for design phase, while further validation is on-going to include different geometries and operating conditions with the goal of reducing both risks and number of tests.

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