This page has only limited features, please log in for full access.
Material extrusion (ME) desktop 3D printing is known to strongly emit nanoparticles (NP), and the need for risk management has been recognized widely. Four different engineering control measures were studied in real‐life office conditions by means of online NP measurements and indoor aerosol modeling. The studied engineering control measures were general ventilation, local exhaust ventilation (LEV), retrofitted enclosure, and retrofitted enclosure with LEV. Efficiency between different control measures was compared based on particle number and surface area (SA) concentrations from which SA concentration was found to be more reliable. The study found out that for regular or long‐time use of ME desktop 3D printers, the general ventilation is not sufficient control measure for NP emissions. Also, the LEV with canopy hood attached above the 3D printer did not control the emission remarkably and successful position of the hood in relation to the nozzle was found challenging. Retrofitted enclosure attached to the LEV reduced the NP emissions 96% based on SA concentration. Retrofitted enclosure is nearly as efficient as enclosure attached to the LEV (reduction of 89% based on SA concentration) but may be considered more practical solution than enclosure with LEV.
Anna‐Kaisa Viitanen; Kimmo Kallonen; Kirsi Kukko; Tomi Kanerva; Erkka Saukko; Tareq Hussein; Kaarle Hämeri; Arto Säämänen. Technical control of nanoparticle emissions from desktop 3D printing. Indoor Air 2021, 31, 1061 -1071.
AMA StyleAnna‐Kaisa Viitanen, Kimmo Kallonen, Kirsi Kukko, Tomi Kanerva, Erkka Saukko, Tareq Hussein, Kaarle Hämeri, Arto Säämänen. Technical control of nanoparticle emissions from desktop 3D printing. Indoor Air. 2021; 31 (4):1061-1071.
Chicago/Turabian StyleAnna‐Kaisa Viitanen; Kimmo Kallonen; Kirsi Kukko; Tomi Kanerva; Erkka Saukko; Tareq Hussein; Kaarle Hämeri; Arto Säämänen. 2021. "Technical control of nanoparticle emissions from desktop 3D printing." Indoor Air 31, no. 4: 1061-1071.
The multiplicity of targets of the 5G and further future technologies, set by the modern societies and industry, lacks the establishment of design methods for the highly multidisciplinary application of wireless platforms for small cells. Constraints are set by the overall energy concept, structural safety and sustainability. Various Smart poles and Light poles exist but it is challenging to define the design drivers especially for a composite load-carrying structure. In this study, the design drivers of a composite 5G smart pole are determined and the connecting design between finite element modelling (FEM), signal penetration and computational fluid dynamics (CFD) for thermal analysis are reported as an interdisciplinary process. The results emphasize the significant effects of thermal loading on the material selection. The physical architecture, including various cutouts, is manipulated by the needs of the mmW radios, structural safety and the societal preferences of sustainable city planning, i.e., heat management and aesthetic reasons. Finally, the paint thickness and paint type must be optimized due to radome-integrated radios. In the future, sustainability regulations and realized business models will define the cost-structure and the response by customers.
Donato Di Vito; Mikko Kanerva; Jan Järveläinen; Alpo Laitinen; Tuomas Pärnänen; Kari Saari; Kirsi Kukko; Heikki Hämmäinen; Ville Vuorinen. Safe and Sustainable Design of Composite Smart Poles for Wireless Technologies. Applied Sciences 2020, 10, 7594 .
AMA StyleDonato Di Vito, Mikko Kanerva, Jan Järveläinen, Alpo Laitinen, Tuomas Pärnänen, Kari Saari, Kirsi Kukko, Heikki Hämmäinen, Ville Vuorinen. Safe and Sustainable Design of Composite Smart Poles for Wireless Technologies. Applied Sciences. 2020; 10 (21):7594.
Chicago/Turabian StyleDonato Di Vito; Mikko Kanerva; Jan Järveläinen; Alpo Laitinen; Tuomas Pärnänen; Kari Saari; Kirsi Kukko; Heikki Hämmäinen; Ville Vuorinen. 2020. "Safe and Sustainable Design of Composite Smart Poles for Wireless Technologies." Applied Sciences 10, no. 21: 7594.
Design for additive manufacturing is adopted to help solve problems inherent to attaching active personal sampler systems to workers for monitoring their breathing zone. A novel and parametric 3D printable clip system was designed with an open source Computer-aided design (CAD) system and was additively manufactured. The concept was first tested with a simple clip design, and when it was found to be functional, the ability of the innovative and open source design to be extended to other applications was demonstrated by designing another tooling system. The clip system was tested for mechanical stress test to establish a minimum lifetime of 5000 openings, a cleaning test, and a supply chain test. The designs were also tested three times in field conditions. The design cost and functionalities of the clip system were compared to commercial systems. This study presents an innovative custom-designed clip system that can aid in attaching different tools for personal exposure measurement to a worker’s harness without hindering the operation of the worker. The customizable clip system opens new possibilities for occupational health professionals since the basic design can be altered to hold different kinds of samplers and tools. The solution is shared using an open source methodology.
Kirsi Kukko; Jan Sher Akmal; Anneli Kangas; Mika Salmi; Roy Björkstrand; Anna-Kaisa Viitanen; Jouni Partanen; Joshua M. Pearce. Additively Manufactured Parametric Universal Clip-System: An Open Source Approach for Aiding Personal Exposure Measurement in the Breathing Zone. Applied Sciences 2020, 10, 6671 .
AMA StyleKirsi Kukko, Jan Sher Akmal, Anneli Kangas, Mika Salmi, Roy Björkstrand, Anna-Kaisa Viitanen, Jouni Partanen, Joshua M. Pearce. Additively Manufactured Parametric Universal Clip-System: An Open Source Approach for Aiding Personal Exposure Measurement in the Breathing Zone. Applied Sciences. 2020; 10 (19):6671.
Chicago/Turabian StyleKirsi Kukko; Jan Sher Akmal; Anneli Kangas; Mika Salmi; Roy Björkstrand; Anna-Kaisa Viitanen; Jouni Partanen; Joshua M. Pearce. 2020. "Additively Manufactured Parametric Universal Clip-System: An Open Source Approach for Aiding Personal Exposure Measurement in the Breathing Zone." Applied Sciences 10, no. 19: 6671.
A conjugate heat transfer (CHT) study of a liquid cooling heat exchanger is carried out using the open source computational fluid dynamics (CFD) library OpenFOAM. The heat exchanger was 3D printed using aluminium and experimentally verified by temperature probing and thermal imaging. The functionality of the heat exchanger in cooling localized heat sources is demonstrated. Three different turbulence models were utilized including k-ω shear stress transport (SST) model, the standard k-ε model and large-eddy simulation (LES). The numerical results indicate that the k-ω SST and LES models produced similar results in terms of flow structures and temperature levels while the k-ε model deviated from the two other models. The scalability of the heat exchanger was numerically demonstrated by comparing the flow uniformity by varying the inlet Reynolds number between 4960 and 14880. The conclusions of the paper consists of the following main results. (1) The numerical results indicate that the flow uniformity in the channels is noted to be affected by the flow structures before and after the fin system. (2) The simulated hot-spot temperatures were noted to be relatively sensitive to the predicted flow laminarization inside the channels. (3) The heat exchanger was shown to be functional and to maintain cool surface temperatures in the simulations and the experiments. Additionally, the used CHT solver in OpenFOAM is tested and verified in different ways.
Alpo Laitinen; Kari Saari; Kirsi Kukko; Petteri Peltonen; Erkki Laurila; Jouni Partanen; Ville Vuorinen. A computational fluid dynamics study by conjugate heat transfer in OpenFOAM: A liquid cooling concept for high power electronics. International Journal of Heat and Fluid Flow 2020, 85, 108654 .
AMA StyleAlpo Laitinen, Kari Saari, Kirsi Kukko, Petteri Peltonen, Erkki Laurila, Jouni Partanen, Ville Vuorinen. A computational fluid dynamics study by conjugate heat transfer in OpenFOAM: A liquid cooling concept for high power electronics. International Journal of Heat and Fluid Flow. 2020; 85 ():108654.
Chicago/Turabian StyleAlpo Laitinen; Kari Saari; Kirsi Kukko; Petteri Peltonen; Erkki Laurila; Jouni Partanen; Ville Vuorinen. 2020. "A computational fluid dynamics study by conjugate heat transfer in OpenFOAM: A liquid cooling concept for high power electronics." International Journal of Heat and Fluid Flow 85, no. : 108654.
Large-Eddy Simulation of heat transfer in plate and pin fin heat exchangers is carried out under constant surface temperature assumption while resolving the surface heat flux by a dense mesh of 28 M cells. The heat exchangers are mounted inside a pipe in a highly constrained space. The heat transfer takes place by forced convection at ReD=20000. The numerical simulations are validated by comparison of velocity profiles against experimental flow measurements on 3D-printed aluminium heat exchangers. Both the experiments and simulations indicate higher rate of heat transfer on the outer fins. The numerical findings indicate that, for the plate heat exchanger, the average Nusselt number of the outermost fins is approximately 50% larger than at the inner fins (Nu=7.54). For the pin fin heat exchanger, we observe a 20% increase in the Nusselt number between the inner and the outer fins. A strongly localized vortex shedding region is observed for the pin fin heat exchanger increasing the local heat transfer by a factor of two. In contrast, for the planar fins, the flow appears steady and laminar in the interior. In addition to strong flow diversion observed for both geometries, we show that for the pin fin array, almost 50% of the flow that enters the heat exchanger leaks to the clearances through the side and tip gaps. For the planar fins, the respective leakage is only 30%. Numerical evidence is also provided on the relevance of variety of flow phenomena including recirculation zones, vortex shedding, flow laminarization as well as flow separation and reattachment, all affecting the local heat transfer.
Petteri Peltonen; Kari Saari; Kirsi Kukko; Ville Vuorinen; Jouni Partanen. Large-Eddy Simulation of local heat transfer in plate and pin fin heat exchangers confined in a pipe flow. International Journal of Heat and Mass Transfer 2019, 134, 641 -655.
AMA StylePetteri Peltonen, Kari Saari, Kirsi Kukko, Ville Vuorinen, Jouni Partanen. Large-Eddy Simulation of local heat transfer in plate and pin fin heat exchangers confined in a pipe flow. International Journal of Heat and Mass Transfer. 2019; 134 ():641-655.
Chicago/Turabian StylePetteri Peltonen; Kari Saari; Kirsi Kukko; Ville Vuorinen; Jouni Partanen. 2019. "Large-Eddy Simulation of local heat transfer in plate and pin fin heat exchangers confined in a pipe flow." International Journal of Heat and Mass Transfer 134, no. : 641-655.
3D printers are currently widely available and very popular among the general public. However, the use of these devices may pose health risks to users, attributable to air-quality issues arising from gaseous and particulate emissions in particular. We characterized emissions from a low-end 3D printer based on material extrusion, using the most common polymers: acrylonitrile-butadiene-styrene (ABS) and polylactic acid (PLA). Measurements were carried out in an emission chamber and a conventional room. Particle emission rates were obtained by direct measurement and modeling, whereas the influence of extrusion temperature was also evaluated. ABS was the material with the highest aerosol emission rate. The nanoparticle emission ranged from 3.7·108 to 1.4·109 particles per second (# s−1) in chamber measurements and from 2.0·109 to 4.0·109 # s−1in room measurements, when the recommended extruder temperature was used. Printing with PLA emitted nanoparticles at the rate of 1.0·107 # s−1 inside the chamber and negligible emissions in room experiments. Emission rates were observed to depend strongly on extruder temperature. The particles’ mean size ranged from 7.8 to 10.5 nanometers (nm). We also detected a significant emission rate of particles of 1 to 3 nm in size during all printing events. The amounts of volatile organic and other gaseous compounds were only traceable and are not expected to pose health risks. Our study suggests that measures preventing human exposure to high nanoparticle concentrations should be adopted when using low-end 3D printers.
Luís Mendes; Anneli Kangas; Kirsi Kukko; Bjarke Mølgaard; Arto Säämänen; Tomi Kanerva; Inigo Flores Ituarte; Marika Huhtiniemi; Helene Stockmann-Juvala; Jouni Partanen; Kaarle Hämeri; Konstantinos Eleftheriadis; Anna-Kaisa Viitanen. Characterization of Emissions from a Desktop 3D Printer. Journal of Industrial Ecology 2017, 21, S94 -S106.
AMA StyleLuís Mendes, Anneli Kangas, Kirsi Kukko, Bjarke Mølgaard, Arto Säämänen, Tomi Kanerva, Inigo Flores Ituarte, Marika Huhtiniemi, Helene Stockmann-Juvala, Jouni Partanen, Kaarle Hämeri, Konstantinos Eleftheriadis, Anna-Kaisa Viitanen. Characterization of Emissions from a Desktop 3D Printer. Journal of Industrial Ecology. 2017; 21 (S1):S94-S106.
Chicago/Turabian StyleLuís Mendes; Anneli Kangas; Kirsi Kukko; Bjarke Mølgaard; Arto Säämänen; Tomi Kanerva; Inigo Flores Ituarte; Marika Huhtiniemi; Helene Stockmann-Juvala; Jouni Partanen; Kaarle Hämeri; Konstantinos Eleftheriadis; Anna-Kaisa Viitanen. 2017. "Characterization of Emissions from a Desktop 3D Printer." Journal of Industrial Ecology 21, no. S1: S94-S106.