| 1. |
- Rehfeld, Nadine, et al.
(författare)
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Round-Robin Study for Ice Adhesion Tests
- 2024
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Ingår i: Aerospace. - : Multidisciplinary Digital Publishing Institute (MDPI). - 2226-4310. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Ice adhesion tests are widely used to assess the performance of potential icephobic surfaces and coatings. A great variety of test designs have been developed and used over the past decades due to the lack of formal standards for these types of tests. In many cases, the aim of the research was not only to determine ice adhesion values, but also to understand the key surface properties correlated to low ice adhesion surfaces. Data from different measurement techniques had low correspondence between the results: Values varied by orders of magnitude and showed different relative relationships to one another. This study sought to provide a broad comparison of ice adhesion testing approaches by conducting different ice adhesion tests with identical test surfaces. A total of 15 test facilities participated in this round-robin study, and the results of 13 partners are summarized in this paper. For the test series, ice types (impact and static) as well as test parameters were harmonized to minimize the deviations between the test setups. Our findings are presented in this paper, and the ice- and test-specific results are discussed. This study can improve our understanding of test results and support the standardization process for ice adhesion strength measurements.
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| 2. |
- Shakeri, Amid, et al.
(författare)
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Impact of occupant modelling on the prediction of airflow around occupants in a ventilated room
- 2007
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Ingår i: The International Journal of Ventilation. - 1473-3315 .- 2044-4044. ; 6:2, s. 129-144
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Tidskriftsartikel (refereegranskat)abstract
- Localized ventilation systems typically create highly asymmetric or non-isothermal environments around occupants with significant vertical temperature gradient and highly non-uniform airflow regimes that could be directed toward a segment of the body. These effects may have pronounced impact on occupant's thermal comfort. The airflow field and temperature distribution near the occupant can be determined either by performing full-scale measurements or by simulation methods. Usually, human subjects or manikins are used in field studies involving measurement techniques. However, as an alternative to full-scale measurement, Computational Fluid Dynamics (CFD) has been proven to be a practical and valuable tool for predicting the airflow field. At the same time, the accuracy of the predictions of the local airflow within the microclimate of the occupant is highly dependent on the proper modelling of the occupant itself. The human body not only has a complicated physical shape, but also has complex thermo-physiological properties. Modelling of all these aspects is a formidable challenge and an extremely time-consuming task. Therefore, various simplifications have been made in order to decrease the level of complexity so that the computation may be performed with the available computer resources. This paper reports the results of a detail numerical simulation to study the impact of occupant modelling on the airflow and temperature distribution and their influences on the occupant's thermal comfort. First, the predictions made by the CFD model were compared with experimental data that were measured in a specially designed experimental chamber. Good agreement was observed. Four type of configuration were used to model the occupant: a conventional block form, three-node, six-node and finally eight-node configurations. Further simulations were carried out to investigate the assumption of uniform heat distribution. An assessment of uniform and non-uniform heat distribution scenarios for various occupant configurations and ventilation systems showed that the assumption of uniform heat distribution is valid for a wide range of operating conditions.
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| 3. |
- Vardelle, Armelle, et al.
(författare)
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Erratum to The 2016 Thermal Spray Roadmap
- 2017
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Ingår i: Journal of thermal spray technology (Print). - : Springer Science and Business Media LLC. - 1059-9630 .- 1544-1016. ; 26:5, s. 985-986
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Vardelle, Armelle, et al.
(författare)
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The 2016 Thermal Spray Roadmap
- 2016
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Ingår i: Journal of thermal spray technology (Print). - : Springer Science and Business Media LLC. - 1059-9630 .- 1544-1016. ; 25:8, s. 1376-1440
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Tidskriftsartikel (refereegranskat)abstract
- Considerable progress has been made over the last decades in thermal spray technologies, practices and applications. However, like other technologies, they have to continuously evolve to meet new problems and market requirements. This article aims to identify the current challenges limiting the evolution of these technologies and to propose research directions and priorities to meet these challenges. It was prepared on the basis of a collection of short articles written by experts in thermal spray who were asked to present a snapshot of the current state of their specific field, give their views on current challenges faced by the field and provide some guidance as to the R&D required to meet these challenges. The article is divided in three sections that deal with the emerging thermal spray processes, coating properties and function, and biomedical, electronic, aerospace and energy generation applications. © 2016, ASM International.
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| 5. |
- Yeganehdoust, Firoozeh, et al.
(författare)
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A comparison of bioinspired slippery and superhydrophobic surfaces : Micro-droplet impact
- 2021
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Ingår i: Physics of fluids. - : AMER INST PHYSICS. - 1070-6631 .- 1089-7666. ; 33:2
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Tidskriftsartikel (refereegranskat)abstract
- Slippery lubricant impregnated surfaces (SLIPSs/LISs) exhibit remarkable features of repellency and droplet mobility to a broad range of complex fluids. Their performance in micro-droplet repellency has received less attention. In this study, the anti-wetting performance of SLIPSs in comparison to superhydrophobic surfaces (SHSs) is investigated for the micro-droplet impact on different textured surfaces. Different series of square-pillar arrays are modeled to consider the effect of surface morphology on droplet hydrodynamics. A multiphase numerical model in conjunction with an accurate contact angle method has been implemented to analyze details of three immiscible phases during the droplet impact on the SLIPS. Our findings revealed that on the SLIPS with a low-density micro-textured surface where the effect of lubricant is more significant, droplet repellency and mobility are improved compared to SHSs. It was illustrated that on the SLIPS, droplet pinning decreased significantly and in low Weber number cases where the effect of lubricant is more noticeable, partial bouncing occurred. It was also observed that slippery surfaces with a low-density of micro-pillars exhibit bouncing behavior, which indicated the repellency effect of lubricant in droplet hydrodynamics. Although micro-droplets failed to recoil at a higher Weber number ( W e similar or equal to 160) on both the SHS and the SLIPS, droplet penetration within the micro-structured surface was considerably smaller on the SLIPS.
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