Mechanical engineering design
Al-Zubaydi, AYT & Dartnall, WJ 2014, 'Design and Modelling of Water Chilling Production System by the Combined Effects of Evaporation and Night Sky Radiation', Journal of Renewable Energy, vol. 2014, pp. 1-8.View/Download from: UTS OPUS or Publisher's site
The design and mathematical modelling of thermal radiator panel to be used primarily to measure night sky radiation wet coated surface is presented in this paper. The panel consists of an upper dry surface coated aluminium sheet laminated to an ethylene vinyl acetate foam backing block as an insulation. Water is sprayed onto the surface of the panel so that an evaporative cooling effect is gained in addition to the radiation effect; the surface of a panel then is wetted in order to study and measure the night sky radiation from the panel wet surface. In this case, the measuring water is circulated over the upper face of this panel during night time. Initial TRNSYS simulations for the performance of the system are presented and it is planned to use the panel as calibrated instruments for discriminating between the cooling effects of night sky radiation and evaporation.
Dartnall, WJ 1986, 'A pump.'.
A borehole pump which avoids the use of a piston sealing within a cylinder, comprises a tubular pump body closed at its lower end by a non return inlet valve and slidably supporting through a seal at its upper end a reciprocating riser pipe likewise closed at its lower end by a non return outlet valve. An upward stroke of the riser pipe draws fluid into the pump body via the inlet valve whilst downward movement expels fluid from the body via the outlet valve and through the riser. (A.E.H.)
Al-Zubaydi, AYT, Hong, G & Dartnall, WJ 2016, 'CFD Modelling and Analysis of Different Designs Plate Heat Exchangers', Proceedings of the 10th Australasian Heat and Mass Transfer Conference, Australasian Heat and Mass Transfer Conference, Queensland University of Technology, Brisbane, Australia, pp. 145-152.View/Download from: UTS OPUS
The indirect evaporative cooling system and heat recovery system utilize the return (secondary) air to condition the fresh (primary) air by means of air-to-air heat exchange between the two streams. The temperature difference between the primary and secondary air streams in indirect evaporative cooling system is relatively small. Therefore, efficient heat exchangers should be used since they play a major role in the overall system performance and economics. The parallel plate type heat exchangers have been widely adopted in Indirect Evaporative Cooling (IEC) systems due to their high efficiency in operating at small temperature difference. In this paper we present a theoretical analysis of different designs of counter flow aluminium plate type heat exchanger and results of CFD analysis of pressure drop, flow velocity and thermal effectiveness. For improving the heat transfer between the plates and minimizing the energy loss, the analysis proves useful in the optimization method for selecting parameters of the plate heat exchangers.
Dartnall, WJOHN, Reizes, JOHNA & Hong, G 2016, 'What is Heat Transfer at its most Fundamental Level? Using simple Molecular Dynamic Simulations to gain an Understanding at the Conceptual Level', 10th Australasian Heat & Mass Transfer Conference, Queensland University of Technology, Brisbane.View/Download from: UTS OPUS
Molecular motion is often at the heart of heat transfer. Molecular dynamic (MD) modelling is becoming a valuable tool in both gaining an understanding of heat transfer processes and in evaluating heat transfer situations. This paper presents some simple models employing MD simulations based on Newtonian mechanics that show potential in the teaching of heat transfer at the conceptual level and that introduce engineers and scientists to the relatively new tool of Molecular Dynamic Simulation.
Dartnall, WJ & Reizes, JA 2013, 'A new way to present the important but difficult topic of statistical mechanics to engineers', ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), International Mechanical Engineering Congress & Exposition, ASME, San Diego, California, USA.View/Download from: UTS OPUS or Publisher's site
As a subject in an engineering course, Engineering Thermodynamics has earned a reputation for being difficult to understand. Quite often students practice many problems until they can do the assigned tasks, but they still feel mystified by concepts such as entropy. Even though we may use them competently, energy, enthalpy and temperature are not necessarily well understood at a concept level. Statistical Mechanics provides an excellent way of understanding the concepts more fundamentally but the traditional mathematical derivations in Statistical Mechanics require considerable time and effort before a learner gains the comfort of familiarity. Various approaches using spread-sheets to construct combinatorial illustrative examples have been published. An approach based on molecular dynamic simulation is presented in this paper, in which comparisons between actual outcomes of simulations based solely on Newtonian mechanics are compared with the probability based models. Accordingly, this approach allows explanations which meet the objective of demystifying some of the concepts that have hitherto been the bane of undergraduate thermodynamics. Copyright © 2013 by ASME.
Roser, HM, Dartnall, WJ & ASME 2013, 'A FRAMEWORK FOR ENHANCING OUTSIDE-THE-BOX THINKING IN ENGINEERING DESIGN, DEMONSTRATED ON A CASE STUDY', INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION - 2012, VOL 3, PTS A-C: DESIGN, MATERIALS, AND MANUFACTURING, pp. 357-366.
Anderson, P, Wonson, J, Dartnall, WJ & ASME 2012, 'RIGOROUS DESIGN PROCESS FOR A GROUNDWATER PUMP FOR LOW-YIELD WATER WELLS: A CASE STUDY', PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION 2010, VOL 3, PTS A AND B, pp. 787-796.
Dartnall, WJ & Reizes, JA 2012, 'A new approach to understanding engineering thermodynamics from its molecular basis', ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE), ASME International Mechanical Engineering Congress and Exposition, ASME, USA, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
Engineering Thermodynamics is that engineering science in which students learn to analyze dynamic systems involving energy transformations, particularly where some of the energy is in the form of heat. It is well known that people have difficulty in understanding many of the concepts of thermodynamics; in particular, entropy and its consequences. However, even more widely known concepts such as energy and temperature are not simply defined or explained. Why is this lack of understanding and clarity of definition prevalent in this subject? Older engineering thermodynamics textbooks (often containing the words heat engines in the title) had a strong emphasis in their early chapters on the general physical details of thermodynamic equipment such as internal and external combustion engines, gas compressors and refrigeration systems. The working fluid in these systems might expand or contract while heat, work and mass might cross the system boundary. The molecular workings within the thermodynamic fluid are not of prime concern to the engineer even though they are to a physicist or chemist. Modern engineering thermodynamics textbooks place great emphasis on mathematical systems designed to analyze the behavior and performance of thermodynamic devices and systems, yet they rarely show, at least early in their presentation, graphical images of the equipment; moreover, they tend to give only passing reference to the molecular behavior of the thermodynamic fluid. This paper presents some teaching strategies for placing a greater emphasis on the physical realities of the equipment in conjunction with the molecular structure of the working fluid in order to facilitate a deeper understanding of thermodynamic performance limitations of equipment. Copyright © 2012 by ASME.
Roser, HM & Dartnall, WJ 2012, 'A Framework for Enhancing Outside-the-box Thinking in Engineering Design, Demonstrated on a Case Study', Proceedings of the ASME 2012 International Mechanical Engineering Congress & Exposition, International Mechanical Engineering Congress & Exposition, ASME Publishing, Houston, Texas, USA, pp. 1-10.View/Download from: UTS OPUS
This paper introduces a framework for enhancing creative thinking in engineering design. As a flexible methodology, the proposed Creative Engineering Design (CED) framework integrates a new concept development tool, the Concept Assessment Taxonomy (CAT), which constitutes the core of the proposed methodology. By combining the procedures of concept generation, evaluation and selection in a single matrix, the CAT aims to systematize and simplify the overall conceptualization process, while delivering design process transparency. Early trials have shown the effectiveness of the CED framework in offering procedural guidance and a better comprehension of the multifaceted nature of engineering design. It complements well-established textbook-methods in an effort to reduce ad-hoc and trial-and-error approaches, while minimizing decision-making based on intuition and guesswork. In order to demonstrate its usefulness within a real world context, the proposed methodology is applied to a case study in the field of mechanical design: a new mechanical fuel injection system capable of curbing small engine emissions.
Dartnall, WJ & Reizes, J 2011, 'MOLECULAR DYNAMIC COMPUTER SIMULATION MODELS FOR TEACHING THERMODYNAMIC PRINCIPLES', Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition IMECE2011, International Mechanical Engineering Congress & Exposition, ASME, Denver, Colorado, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
Modern mechanical engineers need to learn more than the traditional classical approaches to thermodynamics and heat transfer. Matter is comprised of molecules and in many situations the behavior of these molecules may be modeled using hard spheres whose motion is governed by Newtonian mechanics. This is particularly true in those situations involving relatively low density gases, that are valuable in introducing the concepts of thermodynamics. This paper presents some models that have been developed using simple-to-use software that students can handle in a time-efficient way during class-room situations, using only Newtonian Mechanics. Experience indicates that students have many conceptual difficulties when studying engineering thermodynamics. Simple molecular dynamic approaches promise to give students a more intuitive understanding of these thermal areas.
Anderson, P., Wonson, J. & Dartnall, W.J. 2010, 'Rigorous Design Process for a Groundwater Pump for Low-Yield Water Wells: A Case Study', Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition (IMECE2010), ASME International Mechanical Engineering Congress and Exposition, ASME, Vancouver, British Columbia, Canada, pp. 1-10.View/Download from: UTS OPUS
Ground-water pumping in remote areas, such as Australian farms, was for many years traditionally done by wind pumps in order to satisfy the needs of stock. Since the 1980's solar pumps of varying designs have become popular for pumping water from farm dams and tube wells. Wind pumps, solar pumps, engine or electric motor driven pumps and even animal/human powered pumps have a future in many remote situations in the world for stock watering, irrigation and for village water supply in developing countries. In these markets there is a wide-spread view that local manufacture of the pumps is preferable, as is well documented in the literature on village water supply in developing countries. Submersible pumps that are either of the multi-stage centrifugal class or that use the progressive cavity principle have increased in popularity in the low well yield environment. However, where well yields are extremely low the efficiency of these pumps also becomes low and oversized pumps of these kinds are often inappropriately applied. Quite often in the low yield situation, tube wells are also oversized in that they are drilled to large diameters and depths so as to provide storage in order to accommodate the water demand requirements of the user. This practice leads to unnecessary deterioration of both pump and well. Designing for low production volume manufacture presents unique challenges for the designer in attempting to design a robust, versatile but cost-effective product. The design challenges include, achievement of: - high efficiency, reliability, longevity, simplicity, versatility with a minimum parts count, and all this at a low cost. A case study is presented in this paper in which the design issues are outlined. A rigorous design process has been applied in this case study.
Dartnall, WJ & Reizes, J 2010, 'Developing Innovative Teaching Materials That Use Molecular Simulations in Engineering Thermodynamics', Proceedings of the ASME 2010 International Mechanical Engineering Congress & Exposition (IMECE2010), International Mechanical Engineering Congress and Exposition, ASME, Vancouver, British Columbia, Canada, pp. 1-10.View/Download from: UTS OPUS
Traditionally, Engineering Thermodynamics is presented to undergraduate mechanical engineering students from a classical viewpoint. The emphasis in the courses is on analyzing processes involving bulk thermodynamic properties of materials to ascertain the performance of systems of significant size such as internal combustion engines, steam boiler power plants, vapour compression refrigeration systems, gas compressors etc. This emphasis may need to change so that mechanical engineers gain a better understanding of areas such as nanotechnology, fuel cells, photovoltaic cells and solid state electronics. A further need for change, is because thermodynamics, as a subject, has a reputation that many students apply formulae in a rote-like manner and struggle to understand the underlying physics and practicalities. One of our innovations is to use simple one and two dimensional hard sphere simulations to demonstrate the validity of such basic constants as Avogadroâs Number and the Boltzman constant, and then visually demonstrate the ideal gas equation explaining concepts such as temperature and pressure and the way in which they relate to the volume containing a specified number of molecules. The underlying mechanical/physical reasons for the idealizations and processes of thermodynamics can be visually demonstrated by simple hard sphere models in ways that are related to mechanics. We outline some examples of simple simulations and innovative teaching materials that model the molecular (microscopic) behaviour on which macroscopic thermodynamic behaviour depends. Initial trials of some of the ideas that have appeared in past congress papers have been or are currently being trialed. These trials have revealed how students tend to follow the ârote learning of formulae and procedure approachâ rather than the âphysical understandingâ approach.
Dartnall, W.J., Reizes, J., Anstis, G. & ASME 2009, 'DEMYSTIFYING THERMODYNAMICS BY CONNECTING IT WITH MECHANICS', IMECE 2008: ENGINEERING EDUCATION AND PROFESSIONAL DEVELOPMENT, VOL 9, pp. 63-72.
Dartnall, WJ, Reizes, J & Anstis, G 2009, 'Should engineering thermodynamics include a simplified treatment of its underlying molecular basis?', ASME International Mechanical Engineering Congress and Exposition, Proceedings, ASME International Mechanical Engineering Congress and Exposition, ASME, Lake Buena Vista, Florida, pp. 549-558.View/Download from: UTS OPUS
Engineering Thermodynamics is commonly treated at undergraduate level as âclassical thermodynamics and its applicationsâ. Recent publications, using one dimensional simulations employing hard spheres have proposed ways to obtain the laws of thermodynamics. These models help to explain the state laws, the limitation of the Carnot cycle relationship as well as difficult concepts like entropy. The models, although deterministic, are able to demonstrate the probabilistic behaviour, normally explained by the mathematically sophisticated derivations of Statistical Mechanics. Is it time to include a simplified, mechanistic explanation of Engineering Thermodynamics by deriving it from its molecular basis?
Dartnall, WJ, Revel, A & Giotis, V 2009, 'Air-conditioning employing indirect evaporative cooling can be shown to derive its energy from the solar source', ASME International Mechanical Engineering Congress and Exposition, Proceedings Volume 6, ASME International Mechanical Engineering Congress and Exposition, ASME, Florida, USA, pp. 575-580.View/Download from: UTS OPUS or Publisher's site
This paper explains how Indirect Evaporative Cooling (IEC) uses water as a refrigerant. This water refrigerant may be seen as part of the rain cycle, whereby the environment (not a heat pump) returns water as the refrigerant to the system after re-conden
Niu, J & Dartnall, WJ 2009, 'Using the fuzzy method to evaluate manufacturing productivity', ASME International Mechanical Engineering Congress and Exposition, Proceedings, ASME International Mechanical Engineering Congress and Exposition, ASME, Florida, USA, pp. 115-121.View/Download from: UTS OPUS or Publisher's site
This paper introduces a useful method for improvement of the time forecasting of production lines operating at full speed production time (FSPT) and dealing with uncertain time losses. The full speed production time is a major index of the production lineâs performance because it enables direct evaluation of production line output. This measure is called as overall equipment effectiveness (OEE). The fixed theoretically available hours minus time losses such as holidays, broken equipment and raw materials or labor shortages give us the production linesâ full speed production time. The waterfall chart model (WCM) improves the measurement of FSPT and can thereby help decision-makers to evaluate OEE. Unfortunately, there are many uncertain and imprecise factors operating. The fuzzy method can be used to reduce the degree and effect of uncertainty and imprecision . We therefore introduce fuzzy theory into our WCM chart. This will assist decision makers in evaluating uncertainty and imprecision and obtain improved OEE measurements as well as producing better production plans and master production schedules .
Dartnall, WJ, Reizes, J & Anstis, G 2008, 'Demystifying Thermodynamics by connecting it with Mechanics', 2008 ASME International Mrchanical Engineering Congress & Exposition, American Society of Mechanical Engineering, ASME Press, Boston, Massachusetts, USA, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
The laws of thermodynamics provide an adequate basis for the development of classical thermodynamics and for the many empirical relationships used by mechanical and chemical engineers. The laws evolved before the advent of the computer with its ability to handle complex simulations. This led to the classical structure that did not require a molecular view of matter. The concept of entropy grew out of this classical view but, has unfortunately earned a reputation for being something mysterious and difficult. Statistical mechanics, much of which is based on Newtonian mechanics, has the power to remove the mystery. But, because of its mathematical complexity, it has rarely been used by engineers either to clarify understanding or to analyze processes and models. We propose, illustrating with examples, that simple Newtonian mechanical models can be used in place of statistical mechanics at least for the teaching of concepts.
Niu, J & Dartnall, WJ 2008, 'Application of Fuzzy-MRP2 in Fast Moving Consumer Goods manufacturing industry', Proceedings of the 2008 Winter Simulation Conference, Winter Simulation Conference, IEEE, Miami, Florida, USA, pp. 1939-1945.View/Download from: UTS OPUS
Dartnall, WJ & Reizes, J 2007, 'Thermodynamics from a few dynamic particles raises questions as to how temperature and entropy should be perceived and defined', Proceedings of 2007 ASME International Mechanical Engineering Congress and Exposition, American Society of Mechanical Engineering, American Society of Mechanical Engineering, Seattle, USA, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
In a recently developed simple particle mechanics model, in which a single particle represents the working fluid, (gas) in a heat engine, (exemplified by a piston engine) a new approach was outlined for the teaching of concepts to thermodynamic students. By mechanics reasoning, a model was developed that demonstrates the connection between the Carnot efficiency limitation of heat engines, and the Kelvin-Planck statement of Second Law, requiring only the truth of the Clausius statement. In a second paper the model was extended to introduce entropy. The particle's entropy was defined as a function of its kinetic energy, and the space that it occupies, that is analogous to that normally found in classical macroscopic analyses. In this paper, questions are raised and addressed: How should temperature and entropy be perceived and defined? Should temperature be proportional to average (molecular) translational kinetic energy and should entropy be dimensionless?
Roser, H.M. & Dartnall, W.J. 2007, 'Managing Innovative Technologies in Conceptual Engineering Design', Proceedings of CONNECTED 2007 International Conference on Design Education, CONNECTED 2007 International Conference on Design Education, University of New South Wales, University of New South Wales, pp. 1-5.
In this work, a simple method is presented which aims at assisting both engineering students and professional designers in dealing with innovative technologies during the conceptual phase of engineering design. The technique emphasises on determining critical design issues as well as evaluating new technologies early on in order to define a Critical Design Path. Since time and budget constraints often demand prompt design decisions, a systematic, easy-to-follow concept analysis and evaluation framework is introduced, allowing engineers to quickly identify critical design issues. Furthermore, the study indicates that, particularly in absence of essential knowledge within early development stages, experimental design can provide a cost effective method of identifying potential design problems, as long as a suitable design process is in place as well. The evaluation of potential design solutions can be achieved by conceptual prototypes, which may represent a specific critical technology, or embody initial ideas to quickly gain knowledge that is crucial for the development of new design concepts. This allows the designer to reduce intuition and guesswork, whilst detecting unanticipated effects and phenomena, delivering deeper insight and communicating ideas. Several case studies have been conducted, employing the proposed method as an important tool for rapid and goal-oriented conceptual design. Through the proliferation of recent prototyping technologies, along with a reduction of design iterations, the concepts could be developed and verified on a low budget over a short development time.
Roser, HM & Dartnall, WJ 2007, 'Managing new technologies in conceptual engineering design, demonstrated on innovative positive displayment device', Proceedings of the 2007 International Mechanical Engineering Congress & Exposition, American Society of Mechanical Engineering, American Society of Mechanical Engineering, Seatlle, USA, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
In this work, a simple method is presented, assisting engineering designers in dealing with innovative technologies during the conceptual phase of engineering design. The technique emphasises on determining Critical Design Issues, as well as evaluating new technologies early on in order to define a Critical Design Path. Since time and budget constraints often demand prompt design decisions, a systematic, easy-to-follow concept analysis and evaluation framework is introduced, allowing engineers to quickly identify critical design issues.
Dartnall, WJ & Adhikari, AK 2006, 'Designing functional products in the best interest of the user - with a factor 10 reduction in life cycle cost - example: a (solar) air conditioning system', Proceedings of IMECE2006, American Society of Mechanical Engineering, ASME, Chicago, USA, pp. 1-9.View/Download from: UTS OPUS
Dartnall, WJ & Reizes, J 2006, 'A novel approach to the teaching of entropy based on a recent single particle heat engine model', Proceedings of IMECE2006, American Society of Mechanical Engineering, ASME, Chicago, USA, pp. 1-10.View/Download from: UTS OPUS
Dartnall, W.J. 2005, 'A General Approach For Introducing Materials Handling Topics In a Mechanical Engineering Degree Course', Proceedings of IMECE2005, ASME International Mechanical Engineering Congress and Exposition, American Society of Mechanical Engineers (ASME), Orlando, USA, p. DVD.
Dartnall, WJ 2005, 'A general approach for introducing materials handling topics in a mechanical engineering degree course', Manufacturing Engineering and Materials Handling, 2005 Pts A and B, ASME International Mechanical Engineering Congress and Exposition, AMER SOC MECHANICAL ENGINEERS, Orlando, FL, pp. 1455-1463.
Dartnall, WJ & Johnston, SF 2005, 'Life Cycle Product Design (At "Factor 10" Level): A Case Study Involving Innovative Mechanical Design Of a Remote Area Ground Water Pumping System', Proceedings of ASME 2005 International Mechanical Engineering Congress and Exposition (IMECE2005), American Society of Mechanical Engineering, American Society of Mechanical Engineers (ASME), Orlando, Florida, USA, pp. 1-11.View/Download from: UTS OPUS or Publisher's site
For humanity to be able to meet its needs without compromising the ability of future generations to meet their own, we must create a sustainable and customised service economy. For all the people of the world to be able to share in this goal, including both marginal operators in economically developed countries and most farmers in currently less economically developed countries, we need to increase resource productivity by a factor of 10. This paper describes a conceptual design process in which the designer is looking to achieve this factor 10 improvement at a system design level. Order of magnitude upgrading, on the performance of existing products, calls for an innovative approach to the design process. We outline a methodology, Trend-Morph-PDS, and show in a case study how it has been applied to the development of a ground-water pumping system. This type of system is in demand in geographically remote areas, where low well yield rates are typical, and rather complicated wind or solar pumps are commonly used for these low-yield-well pumps.
Dartnall, WJ & Johnston, SF 2005, 'Morphological Analysis (MA) leading to Innovative Mechanical Design', International Conference on Engineering Design (ICED), The Design Society, International Conference on Engineering Design (ICED), The Design Society, Engineers Australia, Melbourne, Australia, pp. 514-515.View/Download from: UTS OPUS
Dartnall, WJ & Reizes, J 2005, 'A Novel Approach to the Teaching of Thermodynamic Cycles and the Laws of Thermodynamics', Proceedings of ASME 2005 International Mechanical Engineering Congress and Exposition (IMECE2005), American Society of Mechanical Engineering, ASME, Orlando, Florida, USA, pp. 1-9.View/Download from: UTS OPUS or Publisher's site
This paper outlines a simple particle mechanics model in which a single particle represents the thermodynamic fluid (gas) in a heat engine (exemplified by a piston engine). By mechanics based reasoning the model demonstrates the connection between the Carnot efficiency limitation of heat engines and the Kelvin-Planck statement of Second Law requiring only the truth of the Clausius statement.
Dartnall, WJ, Johnston, S & ASME 2005, 'Life cycle product design (at "factor 10" level): A case study involving innovative mechanical design of a remote area ground water pumping system', Energy Conversion and Resources - 2005, pp. 451-461.
Dartnall, WJ, Reizes, J & ASME 2005, 'A novel approach to the teaching of thermodynamic cycles and the laws of thermodynamics', Innovations in Engineering Education - 2005: Mechanical Engineering Education; Mechanical Engineering Technology Department Heads, pp. 31-39.
Dartnall, J & Johnston, S 2004, 'Trend-morph-pds, a methodology for innovative (mechanical) engineering design', Proceedings of the 7th Biennial Conference on Engineering Systems Design and Analysis, ESDA 2004, pp. 61-72.
An original design methodology, TREND-MORPH-PDS, for innovative engineering design is presented. The method focuses on combinatorial methods of design while emphasizing the manipulation of form that helps the designer to generate a variety of good design alternatives. Under this approach, innovations are more likely to involve new combinations of existing forms than the introduction of new machine elements. The methodology involves involves starting with general goals, followed by a morphological analysis, and a constructing a product design specification (PDS).
Dartnall, WJ & Johnston, SF 2004, 'Trend-Morph-PDS, A methodology for innovative (mechanical) engineering design', Proceedings of 7th Biennial ASME Conference on Engineering Systems Design and Analysis, American Society of Mechanical Engineering, American Society of Mechanical Engineers, Manchester, UK, pp. 1-10.View/Download from: UTS OPUS or Publisher's site
The paper describes a design methodology, TREND-MORPH-PDS, an original contribution to design science. It is a relatively simple methodology that has grown from efforts to innovate mechanical machines with their strong dependence on solid (geometrical) reasoning. The approach focuses on combinatorial methods of invention/innovation/design emphasizing the manipulation of form (as distinct from the manipulation of function alone) that help the designer to generate a wide range of good design alternatives. The first premise of this approach is that the elements and functions of mature technologies such as mechanical machines are well documented and understood. Thus, innovations are more likely to involve new combinations of existing forms than the introduction of new machine elements. The second premise is that valuable information is available about most elements and the more popular subsystems and machines. That information has evolved, sometimes over time spans ranging to hundreds of years, but usually has not been systematically documented and categorised, thus leaving opportunities to investigate these areas and discover good design possibilities. Further, some valuable information is available only anecdotally or is tightly held by the managements of the companies that have manufactured the device(s) or own the intellectual rights.
Tyree, C., Roser, H.M. & Dartnall, W.J. 2004, 'Pre-evaporated Stratified Injection', Small Engine Technology Conference and Exhibition, Small Engine Technology Conference and Exhibition, Society of Automotive Enhineers International, Craz, Austria, pp. 1-7.View/Download from: UTS OPUS
A natural gas engine based on the principle of a long stroke reciprocating mechanism (LSRM) is proposed. The crankshaft arrangement in a conventional internal combustion (IC) engine will be replaced by a LSRM featuring long stroke and low speed. A major advantage of this LSRM system is that it considerably reduces the side force, which is inherent in conventional crankshaft arrangements. Another advantage is that the LSRM engine will be more compact than an equivalent crank engine operating under the same conditions of speed, power output and so on. The reduced size and complexity of the engine lead to a favorable reduction in manufacturing and, more importantly, maintenance costs. Using gas fuel will allow an increased compression ratio, which is usually limited by the operating nature of the Otto cycle in gasoline engines. With a longer stroke length and lower engine speed, the engine fuel injection system can achieve better engine combustion and performance than current IC engines. This paper reports the preliminary analysis of the LSRM engine. The advantages and anticipated problems are discussed based on a comparison of the LSRM engine and the conventional IC engine. The potential problem of heat loss, which may be caused by the low engine operational speed, was examined through thermodynamic cycle analysis. The results of this analysis show that the heat loss from the LSRM engine will be in the normal range experienced by conventional IC engines if the ambient air is used as the cooling medium. Copyright © 1999 Society of Automotive Engineers, Inc.