[article] Insinööritieteiden korkeakoulu / ENG

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Meaningful Moments at Work: Frames Evoked by In-House and Consultancy Designers
(The Design Journal, 2019) Björklund, Tua; van der Marel, Floris; Konetekniikan laitos; Department of Mechanical Engineering; Design Factory; Design Factory; Design Factory; Design Factory; Insinööritieteiden korkeakoulu; School of Engineering; Factoryt; Factories
Design is increasingly recognized as a competitive advantage for companies, but we know relatively little of the activities and perceptions of designers in different organizational contexts. Based on 69 semi-structured interviews with 34 in-house and 35 consultancy designers, this study investigates the type and framing of 291 reported meaningful moments. We found different dominant experience frames in the two organizational contexts with different connections to innate needs of competence, relatedness and autonomy. Most meaningful moments in both organizations were related to the social context and implications rather than the design activities themselves. The results highlight professional design being an inherently social and contextual activity, urging more research to take an organizationally situated perspective to design.
Effect of contact area on the wear of ultrahigh molecular weight polyethylene in noncyclic pin-on-disk tests
(Elsevier BV, 2017) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
High frequency circular translation pin-on-disc wear testing of UHMWPE using a ball-on-flat contact along a hypotrochoidal track
(Elsevier BV, 2017) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Effect of increased load on the wear of a large diameter metal-on-metal modular hip prosthesis with a high inclination angle of the acetabular cup
(Elsevier, 2016) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Experimental characterisation of sprays resulting from impacts of liquid-containing projectiles
(Elsevier BV, 2015) Hostikka, Simo; Silde, Ari; Sikanen, Topi; Vepsä, Ari; Paajanen, Antti; Honkanen, Markus; Rakennustekniikan laitos; Department of Civil and Structural Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Modelling and analysing fires following aircraft impacts requires information about the behaviour of liquid fuel. In this study, we investigated sprays resulting from the impacts of water-filled metal projectiles on a hard wall. The weights of the projectiles were in the range of 38–110 kg, with 8.6–68 kg water, and the impact speeds varied between 96 and 169 m/s. The overall spray behaviour was observed with high-speed video cameras. Ultra-high-speed cameras were used in backlight configuration for measuring the droplet size and velocity distributions. The results indicate that the liquid leaves the impact position as a thin sheet of spray in a direction perpendicular to the projectile velocity. The initial spray speeds were 1.5–2.5 times the impact speed, and the Sauter mean diameters were in the 147–344 μm range. This data can be used as boundary conditions in CFD fire analyses, considering the two-phase fuel flow. The overall spray observations, including the spray deceleration rate, can be used for validating the model.
Jamming transitions induced by an attraction in pedestrian flow
(American Physical Society (APS), 2017) Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki; Rakennetun ympäristön laitos; Department of Built Environment; Insinööritieteiden korkeakoulu; School of Engineering
We numerically study jamming transitions in pedestrian flow interacting with an attraction, mostly based on the social force model for pedestrians who can join the attraction. We formulate the joining probability as a function of social influence from others, reflecting that individual choice behavior is likely influenced by others. By controlling pedestrian influx and the social influence parameter, we identify various pedestrian flow patterns. For the bidirectional flow scenario, we observe a transition from the free flow phase to the freezing phase, in which oppositely walking pedestrians reach a complete stop and block each other. On the other hand, a different transition behavior appears in the unidirectional flow scenario, i.e., from the free flow phase to the localized jam phase and then to the extended jam phase. It is also observed that the extended jam phase can end up in freezing phenomena with a certain probability when pedestrian flux is high with strong social influence. This study highlights that attractive interactions between pedestrians and an attraction can trigger jamming transitions by increasing the number of conflicts among pedestrians near the attraction. In order to avoid excessive pedestrian jams, we suggest suppressing the number of conflicts under a certain level by moderating pedestrian influx especially when the social influence is strong.
Collective dynamics of pedestrians interacting with attractions
(American Physical Society (APS), 2013) Kwak, Jaeyoung; Jo, Hang-Hyun; Luttinen, Tapio; Kosonen, Iisakki; Rakennetun ympäristön laitos; Department of Built Environment; Insinööritieteiden korkeakoulu; School of Engineering
In order to investigate collective effects of interactions between pedestrians and attractions, this study extends the social force model. Such interactions lead pedestrians to form stable clusters around attractions, or even to rush into attractions if the interaction becomes stronger. It is also found that for high pedestrian density and intermediate interaction strength, some pedestrians rush into attractions while others move to neighboring attractions. These collective patterns of pedestrian movements or phases and transitions between them are systematically presented in a phase diagram. The results suggest that safe and efficient use of pedestrian areas can be achieved by moderating the pedestrian density and the strength of attractive interaction, for example, in order to avoid situations involving extreme desire for limited resources.
Role of polygeneration in sustainable energy system development : Challenges and opportunities from optimization viewpoints
(Elsevier, 2016) Rong, Aiying; Lahdelma, Risto; Energiatekniikan laitos; Department of Energy Technology; Energy efficiency and systems; Insinööritieteiden korkeakoulu; School of Engineering
A sustainable energy system can be treated as a development of the distributed generation concept. It meets energy demands locally from renewable energy or/and high-efficiency polygeneration production technologies, and is characterized by energy and cost efficiency, reliability, and environmental-friendliness.Distributed energy systems typically use renewable energy resources to supply all energy demands, such as heat, cooling, and electric power in an integrated way. However, it seems that too much emphasis is placed on power and associated renewable energy-based power technologies for dealing with sustainability issues in public discussion and the research community. Often, equally important thermal energy (heat and cooling) and polygeneration are ignored. Polygeneration is an energy- efficient technology for generating simultaneously heat and power as well as other energy products in a single integrated process. Energy efficiency contributes significantly to CO2 emission reduction. This paper discusses the role of polygeneration in a distributed energy system and the contributions of polygeneration to the development of sustainable energy systems. The paper also stresses that efficient decision support tools for sustainable polygeneration systems are important to achieve sustainability. First, the joint characteristic of a polygeneration plant that defines the dependency between different energy products is reviewed. Then, typical methods for dealing with polygeneration systems are reviewed. The review attempts to highlight the complexity of polygeneration systems and potential of polygeneration systems to adjust output of different energy products. Next, the challenges of sustainable polygeneration energy systems are discussed. Then some practices for operating polygeneration plants are discussed.
Transient response of a ship to an abrupt flooding accounting for the momentum flux
(Elsevier BV, 2015) Manderbacka, Teemu; Mikkola, Tommi; Ruponen, Pekka; Matusiak, Jerzy; Sovelletun mekaniikan laitos; Department of Applied Mechanics; Insinööritieteiden korkeakoulu; School of Engineering
Numerical non-linear time domain simulation method for damaged ship motionsis presented. Floodwater motion modelling is based on the lumpedmass method with a moving free surface. The ship and floodwater motionsare fully coupled. The variation of the floodwater mass is accounted for. Amodel to account for the flooding ingress transporting the momentum is presented.The experiments of abrupt flooding have shown that the ship mayexperience the first large roll towards the undamaged side, especially when alarge undivided compartment is flooded. The presented time domain modelis validated against the experimental data on the roll damping of the floodedship and transient flooding. Two different initial stability conditions andtwo different compartment layouts are studied. Viscous dissipation of thefloodwater motions is modelled with an equivalent friction coefficient. Theimpact of the viscous damping is studied. Transient flooding tests show thatthe inflow momentum has to be accounted for when the undivided compartment is flooded. The simulation model is capable of capturing the impact of the inflooding jet and the first roll on the opposite side of the damage is reproduced.
Model experiments of the transient response to flooding of the box shaped barge
(Elsevier BV, 2015) Manderbacka, Teemu; Ruponen, Pekka; Kulovesi, Jakke; Matusiak, Jerzy; Sovelletun mekaniikan laitos; Department of Applied Mechanics; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Insinööritieteiden korkeakoulu; School of Engineering; Sähkötekniikan korkeakoulu; School of Electrical Engineering
Coupling of the flooded water and ship motions was studied experimentally.Roll decay tests for one flooded compartment and transient abrupt floodingtests were performed for the box shaped barge model. The tests were conductedto obtain information on the flooding process for the developmentof numerical tools and to provide validation data. Quantitative values onthe effect of flooded water on the roll damping were obtained. Flooded waterbehaves in a different manner in undivided and divided compartments.Flooded water in divided compartment increases roll damping significantly.In undivided compartment roll damping was high at low amount of floodedwater. For higher amounts damping was of the same order as for the intactmodel. Initial flooding is a complex process where the ship and floodedwater motions are coupled. Propagation of the flooding water inside thecompartment, at a dam-break type abrupt flooding, was studied by trackingthe surface of the flooded water. Image processing algorithm was used to obtain the tracked surface. Flooded water volume and its center of gravity were estimated from the tracked surface. Different internal layouts of theflooded compartment can lead to a totally different roll response. The infloodingjet plays an important role on the response in case of the undividedcompartment. While, for a divided compartment, asymmetric flooding dueto the obstructions, causes high heel angle on the damage side.
Effect of CoCr Counterface Roughness on the Wear of UHMWPE in the Noncyclic RandomPOD Simulation
(ASME International, 2017) Saikko, Vesa; Vuorinen, Vesa; Revitzer, Hannu; Konetekniikan laitos; Department of Mechanical Engineering; Kemian laitos; Department of Chemistry; Sähkötekniikan ja automaation laitos; Department of Electrical Engineering and Automation; Insinööritieteiden korkeakoulu; School of Engineering; Kemian tekniikan korkeakoulu; School of Chemical Technology; Sähkötekniikan korkeakoulu; School of Electrical Engineering
Microalgae-utilizing biorefinery concept for pulp and paper industry: Converting secondary streams into value-added products
(Elsevier BV, 2015) Kouhia, Mikko; Holmberg, Henrik; Ahtila, Pekka; Energiatekniikan laitos; Department of Energy Technology; Energy Efficiency and Systems; Energiatehokkuus ja energiajärjestelmät; Insinööritieteiden korkeakoulu; School of Engineering
Traditional pulp and paper industry is in transition due to increased competition and changes in consumption habits. Advanced biorefining is seen as one option to create new business opportunities. This article presents a microalgae-utilizing biorefinery which is integrated into a traditional pulp and paper mill and which produces high-value algal products, fertilizer and biogas from secondary process streams. Presented biorefinery process is validated with mass balances, employing initial data from a Scandinavian pulp and paper mill. Results indicate that the proposed process is technically viable. Production potential is sensitive to light and nutrient availability in algae cultivation, and seasonal changes in irradiance result in significant output variation. The biorefinery process can be generalized to other process industry and wastewater treatment plants that have similar output flows.
Influence of general corrosion on buckling strength of laser-welded web-core sandwich plates
(Elsevier, 2014) Jelovica, Jasmin; Romanoff, Jani; Remes, Heikki; Sovelletun mekaniikan laitos; Department of Applied Mechanics; Marine Technology; Insinööritieteiden korkeakoulu; School of Engineering
The strength of a web-core steel sandwich plate is potentially reduced in a corrosive environment. This study is dedicated to the influence of a reduction in the thickness of the plates as a result of general corrosion on sandwich plate buckling strength and first-fibre failure. Two scenarios are investigated in which corrosion reduces the thickness of (a) the outer sides of the face plates and (b) all surfaces, including the core. The laser weld between the face sheets and the core is assumed to be intact. The assumptions are made on the basis of earlier experimental findings. Critical buckling and geometric non-linear analysis are carried out with the finite element method, with the kinematics being represented using two approaches: (1) equivalent single-layer with first-order shear deformation theory, and (2) a three-dimensional model of the actual geometry of the structure, modelled using shell and connector elements. The former is used to identify the effect of corrosion on the stiffness coefficients and, consequently, the buckling strength. The later is used for verification and for stress prediction during post-buckling. A rapid decrease in the buckling strength was found for corrosion affecting the outer sides of the sandwich plate. The decrease in the buckling strength doubled in the case of the diffusion of moisture (water) into the core. The shear-induced secondary bending of the faces was found to affect the first-fibre yield.
Friction measurement in a hip wear simulator
(SAGE Publications, 2016) Saikko, V.; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
A hip wear simulator with 100 test stations
(IMechE, 2005) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
A12-station anatomic hip joint simulator
(IMechE, 2005) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Effect of contact pressure on wear and friction of ultra-high molecular weight polyethylene in multidirectional sliding
(IMechE, 2006) Saikko, Vesa; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Wear comparison between a dual mobility total hip prosthesis and a typical modular design using a hip joint simulator
(Elsevier, 2010) Saikko, Vesa; Shen, Ming; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
RandomPOD - A new method and device for advanced wear simulation of orthopaedic
(Elsevier, 2011) Saikko, Vesa; Kostamo, Jari; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering
Performance analysis of the RandomPOD wear test system
(Elsevier, 2013) Saikko, Vesa; Kostamo, Jari; Konetekniikan laitos; Department of Mechanical Engineering; Insinööritieteiden korkeakoulu; School of Engineering

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