[lic] Insinööritieteiden korkeakoulu / ENG
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- Advanced heat transfer modelling with application to internal combustion engine CFD simulations
School of Engineering | Licentiate thesis(2011) Nuutinen, MikaAt present, majority of the detailed modelling related to engine performance, gas flow, combustion, and emissions is performed with Computational Fluid Dynamics (CFD) simulations. The Reynolds Averaged Navier Stokes (RANS) turbulence models are most widely utilized due to turbulent flow conditions, complex geometries, and complicated sub models. Although Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) are more accurate than RANS models, their application in engineering simulations is often limited due to high computational costs. Available heat transfer modelling options utilized with RANS turbulence models comply poorly with engine flows. They are either completely inadequate for the particular flow conditions, or their validity requirements may multiply the problem size and computational costs. The work in this thesis concentrates on development of an accurate, engine flow compliant heat transfer I near wall modelling formalism within RANS framework. The model development yields reformulation of the whole near wall treatment, intrinsically improving the entire near wall accuracy of utilized turbulence models. Furthermore, the developed models are universal and by no means restricted to engine simulations alone. This thesis comprises a survey of the research field and three attached original publications. The first publication presents numerical wall function formalism designed to include effects of strong temperature gradient induced density variation on wall heat and momentum transfer models. The objective was to study conjugate heat transfer from charge gas to piston material in order to get estimates for piston surface temperatures and heat loss. The results indicated that the near wall density variation has a significant effect on peak surface temperature and overall heat transfer predictions. The following research indicated that the temperature gradient induced variations of charge gas viscosity, conductivity, and heat capacity affect the heat transfer prediction as well. Furthermore, this new formalism facilitates rigorous computation of the turbulence model source terms in the near wall region. These source terms affect the near wall turbulence level, strongly coupled with the heat and momentum transfer models. Following these ideas in two subsequent publications, advanced models were developed and implemented. A commercial CFD software, Star-CD, extensively utilized in internal combustion engine CFD simulations, was used as a primary platform for model development and simulations. In addition, an in-house CFD solver was programmed for model testing and validation. This thesis contributes to the research field by providing a comprehensive theoretical approach to heat transfer related near wall modelling within RANS framework and complete theory based models directly applicable to engineering CFD simulations. - Advancing Lead User Methodology in the Fuzzy Front-End of Product Development
School of Engineering | Licentiate thesis(2012) Helminen, PiaMost companies have come to realize that in order to remain in business, and especially, gain economic success, they need to be able to identify user needs and respond to those needs. The set of activities that takes place before the actual product development, the fuzzy front-end, plays a critical role in the competition of whose products meet user needs the best. The main characteristics of the future product are decided in the front-end, determining much of the rest of the product development process. Thus user needs can have the greatest influence on the product if already recognized in the front-end. Product development is still regarded mainly as the job of designers and engineers in a company. The lead user approach turns the tables and puts users to the center. Lead users face needs months or years before they become general in the marketplace. Lead users are also positioned to benefit significantly, if these needs are met. The goal of this research is to explore the role of lead users in product development and advance the lead user methodology. Specifically this thesis and the appended publications aim to further improve the concepts and means available for lead user identification, and to gain more understanding and alternative means for transferring (lead) user knowledge. Findings of the thesis include that the challenge of the companies is not only to open up to the possibility that a competitive solution might be developed outside the company, but that it could be developed to meet a need that is identified outside the target market of the product under development. If companies concentrate solely on the needs of the users in the target market, they very possibly miss insights from the lead users. I show that besides high-performance users, also low-performance users can be seen as lead users. In addition, a product is always part of a net of crossing consummation chains in the user’s life, and in user’s standpoint it cannot be seen as unconnected. Recognizing the crossing points of different consummation chains and value systems makes it possible to identify in addition to lead users and situational lead users, also positional lead users. User innovation toolkits have been proposed as a tool to for transferring the need-related (lead) user knowledge to the company. This thesis demonstrates contradictions between the toolkit theory and the optimum content of a toolkit, which leads to the conclusion that creating functional and efficient user innovation toolkits might be too risky a task in most product development cases. I recommend that companies would concentrate on lead user identification. If the lead user has already found a viable solution to his or her need, the solution could be transferred as such. If the lead user is still battling with the unmet need, what is to be transferred is the user need. This can be done through participatory methods, such as the P3D method developed in this thesis. - Betonikantisen sillan pintarakenteiden kestävyys ja elinkaarikustannukset
Insinööritieteiden korkeakoulu | Licentiate thesis(2014) Noponen, Sami - Biologinen typen- ja fosforinpoisto jätevesistä - Nitrifikaation tehostaminen vapaasti kelluvilla kantoainekappaleilla
School of Engineering | Licentiate thesis(2010) Rantanen, PirjoThe enhancing of nitrification with free-swimming carriers was studied on this thesis. In the Literature part the prevailing theory of nitrification was reviewed, as well as biofilm processes and the research concerning biofilms and alternative biological processes to nitrification. In the Experimental part a process with biological nitrogen and phosphorus removal with a nitrifying biofilm was studied. The experiments were conducted in semi-technical scale. The following conclusions were made in the study: The nitrification rate of 1,3 gNO3-N m-2 d-1 is critical in dimensioning, and a higher rate probably cannot be used as the basis of dimensioning, because the maximal rate (2,0 gNO3-N m-2 d-1) cannot be utilized in practice. In a low temperature, e.g. 10 °C, the rate to be chosen would be 0,75 gNO3-N m-2 d-1 or lower. A process similar to the carrier line could be dimensioned to a smaller volume than the process based on bare activated sludge, if the basis of the dimensioning is the lowest temperature of the year following the melting of snow, as is common in Nordic countries. In these limiting conditions the higher nitrification potential of the carrier line became evident more clearly than in normal conditions. When the nitrification rates were compared to those reached by a hybrid process with a fixed carrier combined to activated sludge (Germain et al., 2007), 0,16-0,34 gNH4-N m-2 d-1 (8-9,2 °C) and 0,18-0,80 gNH4-N m-2 d-1 (14-19,5 °C), it can be noticed that the rates reached in this study were higher in respective temperatures. The concentration of dissolved oxygen could be used as a control parameter in a hybrid process. The nitrification in the carrier line was limited by the concentration dissolved oxygen half of the time and the concentration of ammonium half of the time. The optimal running parameters of the carrier line were depending on conditions: return sludge flow 100-150 %, nitrate recycle flow 115-150 %, anoxic recycle flow 110 % and the concentration of dissolved oxygen 3,0-7,5 mg l-1 according to a simplex optimization. All the online analysers needed monitoring with the laboratory analyses process samples. The following further studies arose from this thesis: What would be the minimal size of the carrier line year round at least as well as the activated sludge line? Fitting of a deterministic or other model to a process similar to the carrier line and verifying it. The A study of the temperature dependence of nitrification in a process similar to the carrier line. Studying the interactions between the biofilm and activated sludge considering the optimal: dimensioning of the process, the filling rate of the carrier and the required effective area as well as the( running conditions. The calculation of the sludge age in a process is similar to the carrier line sot, that it would be meaningful considering nitrification as well as the limiting sludge age, and which parameter it depends on. - Business Model Based Concept Generation - Understanding, creating and managing concepts in business
School of Engineering | Licentiate thesis(2016) Sääskilahti, MikkoThis study introduces a new approach called Business Model Based Concept Generation. Concept development in the business environment has been analyzed in the six academic papers included in this thesis. The main task has been to understand what concept development and design means in theory and in practice, and how companies actually develop new concepts in their innovation activities. In this study, Finnish manufacturing companies have been involved widely, ranging from a micro-size enterprise from the northern Lapland to a large, globally operating company in southern Finland. This study found that many companies are extremely product oriented. Concept development does not cover the whole business and much innovation potential is lost when concentrating on tangible products. Companies are familiar with service innovations, but service concept creation is still problematic for the manufacturing companies. On the other hand, an innovation system is not that developed in the companies that produce services. Furthermore, innovation activities rarely reach all the business units, but innovations are seen as part of product development initiatives. In practice, in an average company there are no multidisciplinary teams developing different types of innovations. As a result, companies do not understand the meaning and significance of concepts and concept development, they lack the knowledge, processes and methods for conscious concept generation and concept development. Front-end innovation is so to say unstructured and unmanaged. Companies manage to create successful solutions, but often especially in small companies, the success results from evolutionary development activities by an entrepreneur, not goal-oriented innovation work. Companies are seldom able to recognize the key to success; they have no ability to understand the concept of successful solution. Product-oriented focus in thinking and operations prevent developers and managers from seeing innovations and innovation potential in other dimensions of business. It would help if the concept could be seen as a recipe for ways in which something is made and served. Then the breakthrough solution could be replicated, scaled, varied or applied innovatively, if the concept was clear for the developers. As a summary, the Business Model Based Concept Generation approach would help companies to develop many types of innovations consciously and renew the early phases of product development; an innovative business model should influence product (service) design and vice versa. - Condition management of water distribution systems
School of Engineering | Licentiate thesis(2010) Aksela, KiaThis thesis discusses technical condition management of a water distribution network. The main components of condition management are condition management of the network's assets, hydraulic performance management and water quality management. The ultimate goal is to secure water quality, maintain the service level and to utilise resources in a sensible way with an acceptable level of risk. The techniques and methods utilised today are outdated and do not support proactive condition management - currently only a reactive approach is commonly applied. Before condition management can truly evolve, improvements need to be made in hydraulic management. The most significant contributions of this work are the two methods developed in it. The first is a novel, automated, indirect leakage detection method, which utilizes flow measurement data from the network supplied by a supervisory control and data acquisition system. The second is a new way to perform customer demand estimation based on the sample measurements of residential customers using an automated meter-reading technique. Leakage information aids directly in condition management as it is used as one variable in describing the condition of assets. Demand and leaks combined constitute the load to the network. As the least information is available on the load, its better quantification opens new possibilities in hydraulic calculations. The developed solutions build upon a new approach in the field of network hydraulic management and furthermore in assets condition management. The prevailing techniques are presented briefly and future requirements are established. As a high level contribution, a path towards more effective technical management of the network is shown. The traditional static information is combined with dynamic information 50 that more comprehensive assessment of water distribution system performance and condition can be formed. - The content of constructability; Preliminaries for co-operational development of constructability in Finland
School of Engineering | Licentiate thesis(2015) Tauriainen, Matti Kalervo - Corporate social responsibility practices in real estate business - Is co-operation the key to enhancing sustainability ?
School of Engineering | Licentiate thesis(2015) Andelin, Mia - District heating and cooling as part of smart energy systems
Insinööritieteiden korkeakoulu | Licentiate thesis(2015) Kontu, KaisaEnergy systems are evolving and energy companies are required to take action to achieve higher levels of energy efficiency. Smart cities have been widely under discussion and smart energy systems are considered as the backbone of this approach. District heating and cooling (DHC) businesses are argued to be ‘important tools’ for reaching energy targets. The major objective of this research is to study the spedial characteristics of smart energy systems and how DHC systems are adapting to them. The most important factors for smart thermal grids are intelligence, efficiency, and flexibility in production and consumption, customer involvement, integration with other energy systems, and reliability. This study will present three case studies to highlight energy efficiency measures on the consumer side of a DHC system. The first study concentrates on the benefits of remote measurements and better implementation of a district heating (DH) forecasting model when consumer’s hourly measurements are utilized. The forecasting model was formed using linear regression, based on outdoor temperature data and the social component of the heat consumption. The study shows that forecasting models are more accurate for bigger customers and aggregated groups of customers and in the best cases a rather simple model predicts heat consumption with good accuracy. The second case study focuses on the flexibility of the DH network. The demand-side management (DSM) potential of district-heated residential buildings was determined by cutting heat for one hour during the morning consumption peak. Utilising the results of an earlier study, where the thermal behavior of eight different-aged residential buildings was simulated, the object of this research was to figure out the overall DSM potential of the buildings. The results showed that the thermal behavior of the buildings varies and that the buildings with the best potential for DSM were the ones built during the years 1940-2002. In the larger scale, the momentary heat effect decreased 80 percent due to DSM actions. The last case study concentrates on the original idea of the DH system, which is that heat can be recycled from sources where it otherwise would be wasted. A new business model is presented and critically evaluated, in which heat customers can sell their waste heat back to the energy company at a predetermined price. The pricing model is estimated relative to the waste heat suppliers as well as to the energy company. The results showed that, in general, it is profitable for heat customers to sell their waste heat in situations where the price of electricity is low, because then priming the temperature of the waste heat using heat pumps is affordable. System-wide, the results showed that emission levels were increased in most of the cases due to the priming of the waste heat. Despite of the results, this concept is an important opening for the energy and heat markets to include more waste heat in an energy system and thus decrease primary energy consumption. - Energiatehokkuuden muutosjohtaminen
School of Engineering | Licentiate thesis(2014) Huhtanen, PerttiTutkimuksen aiheena on energiatehokkuuden muutosjohtaminen. Tarkoituksena on avata energiatehokkuus-toimikunnan tarkoittamaa sosiaalisen energiansäästöpotentiaalin käsitettä ja selvittää perusteita, visioita, strategioita ja välineitä olemassa olevan rakennuskannan energiatehokkuuden muutosjohtamiseen ja sen osatekijään muutosviestintään. Muutosviestinnän osapuolina tarkastellaan rakennusten asukkaita, käyttäjiä, käyttö- ja huoltohenkilökuntaa ja käytön johtamista. Käytön johtajana toimivien isännöintiyritysten mahdollisuuksia kehittää ja tarjota energiatehokkuuden muutosjohtamispalveluja pohditaan ja kartoitetaan niissä tarvittavaa osaamista. Tutkimuskysymykseksi muotoutui, millainen voisi olla isännöintiyrityksen energiatehokkuuden muutosjohtamisvisio ja mitä osaamistarpeita siitä seuraa. Tutkimuksen aineisto koostuu isännöinti- ja energia-alan historiallisesta tarkastelusta, muutosvoimia ja visioita kartoittavasta kirjallisuustutkimuksesta, tiedon välittynyttä vaikutusta, sosiaalista tietoa ja tiedon konvergenssia koskevien teorioiden tarkastelusta, kyselytutkimusten ja verkkohaastattelujen analyysistä ja empiirisen aineiston keruusta ja analyysistä kompetenssilaboratoriomenetelmällä. Tutkimuksen metodi on kulttuurihistorialliseen toiminnan teoriaan pohjautuva kehittävä työntutkimus ja siitä johdettu kompetenssilaboratorio, jossa toteutetaan tutkittavan organisaation toimintaan vaikuttavia interventioita. Keskeinen tulos on isännöintiyrityksen energiatehokkuuden muutosjohtamisvisio. Yritys kehittää massaräätälöitävän palvelukonseptin, jossa yritys ottaa vastuun asiakkaan energiatehokkuuden kehittämisestä esimerkiksi viiden vuoden sopimusjakson ajan. Yritys vastaa asiakkaan ja palveluverkoston teknisten varusteiden ja valmiuksien riittävyydestä, sosiaalisen tiedon synnyttämisestä ja hyödyntämisestä ja yhdessä oppimisen tuloksista. Johtopäätöksenä energiatehokkuuden muutosjohtamisessa tarvitaan ensisijaisesti johtamistaitoa, erityisesti viestintätaitoa, ja toissijaisesti teknistä osaamista. Yrityksen oman osaamisen kehittäminen tulee ensisijaisesti suunnata prosessien ja johtamisen hallintaan. Isännöintialan visio energiatehokkuuden muutosjohtamisesta vaikuttaa olevan melko kaukana tulevaisuudessa. Nuoren polven suhtautumisessa energiatehokkuuden muutosjohtamiseen näkyy myönteisiä merkkejä. Jatkotyö tulisi suunnata energiatehokkuuden muutosjohtamismallin kehittämiseen tähtääviin asiantuntijalaboratorioihin. Tutkitusta yrityksestä tai vastaavista voitaisiin koota 4-5 hengen ryhmä, joka tähänastisen kompetenssilaboratoriotyön ja aiemmin hankkimansa isännöintialan ja isännöintimarkkinan tuntemuksensa pohjalta pyrkisi luomaan energiatehokkuuden muutosjohtamismallin ja kokeilemaan sitä 2-3 asiakkaan kanssa. Uusia työkaluja (energiasimulointiohjelmisto, korjausrakentamisen kustannushallintaohjelmisto) voitaisiin harjoitella mahdollisessa TYKE-hankkeessa toteutettavassa asiantuntijalaboratoriossa. - Engineering characteristics of cement stabilized soft Finnish clay
School of Engineering | Licentiate thesis(2009) Hassan, Md. Mamunul - Evaluation of three ice-structure interaction models
Licentiate thesis(1996) Muhonen, AriThis work concentrates on the contact between an ice edge and a vertical indenter face during intermittent crushing. The results of a laboratory indentation test series are analyzed and a description of the physical phenomena occurring at the contact is given. The existing dynamic ice-structure interaction models are reviewed. The ability of three models to simulate representative test results is evaluated. The results of the indentation test series consist of 77 tests of which 23 are analyzed. The tests were carried out in a small basin with a floating sheet of columnar grained freshwater ice. The ice was horizontally loaded with an indenter which was installed in front of a spring-mass system. Special attention was paid to the visual observations in order to find the physical phenomena occurring at the ice deformation process. The ice failure process was cyclic in the whole analyzed parameter space. The apparent crushing frequency was dependent on the indenter velocity and the lowest natural frequency of the structure. The latter also affected the peak force values: the higher the natural frequency the lower the force. The ice failed in flaking. The flakes were formed locally by different size macrocracks which separated the flakes from the parent ice. This lead to a chain reaction which caused the deformation of the whole contact face during the load drop. The resulting ice wedge was crushed during the spring-back phase following the load drop. The results of three representative tests were simulated using three different type dynamic ice-structure interaction models. None of the models performed well when the needed parameter values were obtained straight from the tests or the test conditions. However, when the parameter values were modified, the match improved considerably. - Experimental and theoretical studies of energy efficient convective heat transfer, mass transfer and heat storage
School of Engineering | Licentiate thesis(2013) Meriläinen, Arttu - Fotogrammetrisen mittaus- ja mallinnusprosessin kehittäminen sisätilojen suunnittelua ja muotoilua varten
Insinööritieteiden korkeakoulu | Licentiate thesis(2013) Kurkela, Matti - Foundries as suppliers
School of Engineering | Licentiate thesis(2012) Saarelainen, Tanja - Fundamentals of air curtain design
School of Engineering | Licentiate thesis(2010) Valkeapää, AkiAir curtains are used to reduce doorway-induced thermal losses and the negative effects of draught in situations where ordinary fixed doors are kept open. This paper examines the functionality of air curtains, and related factors, with the aid of measurements made in industrial buildings. To clarify the operating conditions of air curtains, an analysis method was developed during the project based on field research and measurements. In addition, the paper sets out horizontal and vertical upwards blowing air curtains' tightness levels defined with tracer measurement results as the basis. Tightness measurements were conducted to study the energy saving effects of air curtains under the climatic conditions of Finland. The results are presented with the aid of an example calculation in the final section of this paper. When using an air curtain under the correct operating conditions, the achievable tightness is 50 - 80 % in large doorways. The highest tightness level was obtained in the test hall when using an upwards blowing air curtain of the recirculating type (etaac,maxac,max - Georeferencing and stereo model formation of aerial oblique photographs
School of Engineering | Licentiate thesis(2015) Nurminen, Kimmo - Hardness prediction of a laser hybrid welded joint using FE simulation
School of Engineering | Licentiate thesis(2011) Tamminen, Tero - Jäähdytetyn myymäläkalusteen rakenteelliset ja toiminnalliset parametrit
School of Engineering | Licentiate thesis(2011) Sipilä, Tomi T.In a modern day supermarket approximately 45 - 50% of the total electricity consumption is consumed by the refrigerating of perishable food products. Open refrigerated display cases that have been used to display the products have a significant contribution to that. The cabinets have been favoured due their boost in sales but the main disadvantage is their high energy consumption thus 70 - 75% of the energy load is transferred through an opening. The most trivial method to reduce the consumption is to equip the cabinets with doors and lids. Nevertheless that has not gained an acceptance in major supermarket chains yet and thus other means must be applied. According to the previous air curtain and display cases studies the heat flow from ambient to the air curtain can be expressed as a function of fourteen constructional and operational parameters of the display case. This research project used the technique of experimental studies to analyse the influences of twelve of these parameters on an air curtain equipped multi-deck display case. During the course of the study a custom designed experimental facility was constructed and located into the climate chamber, where ambient conditions were controlled and held constant during the measurements. The results of the measurements indicated that the parameters air curtain initial velocity distribution and its initial turbulence, air curtain Reynolds number, air flow rate through a perforated back panel and location angle of an air curtain intake grill have the most significant influence on the performance. When a construction of the display case is considered the last three parameters are the most important ones. Their influence on the target variables, cooling load and maintained product temperatures had a divergent pattern and thus they are practically defining the basic level of the cabinet performance. The rest of the parameters can be applied as a fine-tuning of the performance only. - Key issues of mass valuation in countries under transition
School of Engineering | Licentiate thesis(2012) Tomson, AlvarDuring the last two decades there have been phenomenal changes in political structures in post-socialist Central and Eastern European countries. Those changes have been based on different principles, but have all resulted in major land reforms. As real estate in terms of a free market was something unknown for those countries, a lot of problems have followed the reform process. This research is focused on the interpretation of the key issues of mass valuation in circumstances of undeveloped property markets in countries in transition. The analysis was grounded on the case study of mass valuation systems for real estate taxation in the Baltic countries and on the case study of mass valuation systems for land restitution in Albania. Although there were differences in the time frames, in the aim of introducing market valuations, etc. the same topics were covered. Thus, topics like the differences between mass appraisals and single-property valuations, market and non-market value, the reappraisal cycle, valuation date, etc. are discussed from a theoretical point of view and practical aspects are presented as part of the case studies. The discussion section contains consideration within a wider context and inspects the relationship of this investigation with earlier research. Combining the conclusions made based on development of mass valuation systems in Baltic countries (analysed period 1993-2003) and Albania (analysed period 2005-2006), two conclusions can be drawn:. The first, the analysis shows that deviations in interpretation of the key issues of mass valuation are rather typical for all countries handled in the current research. There seems to be no significant distinction based on the level of development of the property system or some other relevant characteristics. The second conclusion derived from the observations made in the context of development of mass valuation systems in circumstances of undeveloped property markets in countries in transition is that external influences have turned valuation into part of the political decision-making process. Although it was more clearly identified within the Albanian context, this was to a certain level typical in the Baltic countries as well. The practical implications of the findings occur at two levels:. First, at the general level, the research has provided an understanding about the development of mass valuation systems in countries in transition where undeveloped market circumstances are rather typical. A better understanding of these cases can provide lessons as to how other countries might develop (or might not develop) their own systems. At the country level, the findings can be used for stimulating the mass valuation systems which in the wider context are a part of the fundamentals of the taxation system (reform process) and national economy.