ORCID Profile
0000-0002-0153-9978
Current Organisation
University of Sydney
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Publisher: Springer International Publishing
Date: 2017
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 03-2009
Publisher: Elsevier BV
Date: 12-2021
Publisher: Wiley
Date: 11-07-2018
DOI: 10.1002/TAL.1516
Publisher: Elsevier BV
Date: 04-2021
Publisher: Springer Science and Business Media LLC
Date: 18-07-2018
Publisher: Elsevier BV
Date: 04-2020
Publisher: SAGE Publications
Date: 14-10-2015
Abstract: The aim of this study was to provide more reliable and robust norms for the Motion Sickness Susceptibility Questionnaire (MSSQ-Short). The previous norms for the MSSQ-Short involved a small s le overrepresenting younger female participants, which may provide misleading estimates of susceptibility in the general population. We measured MSSQ-Short scores in a s le of 1,711 members of the general public in New Zealand and Australia. The s le is 6.6 times larger than the original norm s le, and age and gender closely match the general population. Compared with the current study, the original norms underrepresent those of high susceptibility by a factor of 3.6, or 0.52 standard deviations. The analysis detected higher levels of susceptibility in females and significantly lower susceptibility in those ages 65 years and older. This study provides the largest s le of MSSQ-Short scores with more representative demographic characteristics of age and gender. Despite the potential for a self-selection bias toward high levels of susceptibility, we argue that the current norms provide more reliable and robust norms than the original s le. These updated norms provide the tools for researchers and designers to evaluate the likely effect of various motion environments on the general population. Robust norm data can inform research, including general motion sickness research and environmental design.
Publisher: AIP Publishing
Date: 21-03-2016
DOI: 10.1063/1.4944555
Abstract: This letter presents the effects that fitting fins to various corners of a square-prism galloping-based piezoelectric energy harvester (PEH) has on its performance, based on results from a series of wind tunnel model tests. The results show that attaching fins to the leading edge significantly improves the efficiency of the harvester, achieving a maximum power 2.5 times that attained by a plain square prism PEH. Furthermore, a length that is 1/6 of the prism's cross-sectional width is found to be optimal for fins that are attached to the harvester.
Publisher: Elsevier BV
Date: 04-1992
Publisher: American Society of Civil Engineers (ASCE)
Date: 11-1986
Publisher: Informa UK Limited
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 24-10-2010
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 11-2011
Publisher: Springer Science and Business Media LLC
Date: 24-05-2012
DOI: 10.1007/S00221-012-3118-4
Abstract: We have previously shown that sinusoidal galvanic vestibular stimulation, a means of selectively modulating vestibular afferent activity, can cause partial entrainment of sympathetic outflow to muscle and skin in human subjects. However, it influences the firing of afferents from the entire vestibular apparatus, including the semicircular canals. Here, we tested the hypothesis that selective stimulation of one set of otolithic organs-those located in the utricle, which are sensitive to displacement in the horizontal axis-could entrain sympathetic nerve activity. Skin sympathetic nerve activity (SSNA) was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in 10 awake subjects, seated (head vertical, eyes closed) on a motorised platform. Slow sinusoidal accelerations-decelerations (~4 mG) were applied in the X (antero-posterior) or Y (medio-lateral) direction at 0.08 Hz composite movements in both directions were also applied. Subjects either reported feeling a vague sense of movement (with no sense of direction) or no movement at all. Nevertheless, cross-correlation analysis revealed a marked entrainment of SSNA for all types of movements: vestibular modulation was 97 ± 3 % for movements in the X axis and 91 ± 5 % for displacements in the Y axis. For each sinusoidal cycle, there were two major peaks of modulation-one associated with acceleration as the platform moved forward or to the side, and one associated with acceleration in the opposite direction. We interpret these observations as reflecting inertial displacement of the stereocilia within the utricle during acceleration, which causes a robust vestibulosympathetic reflex.
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 08-2013
Publisher: Elsevier BV
Date: 11-1999
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 05-2018
Publisher: SAGE Publications
Date: 13-10-2017
Abstract: Low airflow or poor outdoor ventilation around building blocks can negatively influence pollutant dispersion in the surroundings and indoor air quality, and increase the risks of airborne transmission of infectious diseases. However, there have been few studies addressing the wind environment, thermal comfort and other concerns at the pedestrian level. Buildings with a lift-up design may have a number of impacts on the pedestrian-level wind and thermal environments. Three building configurations that resulted in the lowest wind speed zones were identified from a previous study. A 3.5 m high open ground floor was added to each of the three configurations, and scale models of the three designs were studied in a wind tunnel to assess their influences on airflow and ventilation around the buildings. Undesirable areas of low wind speed leading to poor air ventilation and, on the other side of extreme, areas of discomfort due to strong wind conditions were both identified, and their practical implications are discussed.
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 12-1993
Publisher: Informa UK Limited
Date: 11-11-2021
Publisher: ASMEDC
Date: 2006
DOI: 10.1115/PVP2006-ICPVT-11-94009
Abstract: A series of wind tunnel sectional model dynamic tests were conducted to examine the effects of torsional-to-vertical natural frequency ratio on the aerodynamic and dynamic properties of bridge decks. The natural frequency ratios tested were around 2.2:1 and 1.2:1 respectively, with the fundamental vertical natural frequency held constant for all the tests. Two 2.9 m long sectional bridge models, one simulating the cross-section of a twin-deck bridge with a gap-width to total chord ratio of about 16% and the other with zero gap-width to approximate a thin plate, were tested to determine whether the effects of frequency ratio are similar for bridge decks with different cross-section shapes. The results of wind tunnel tests suggest that for the model with zero gap-width, the flutter derivatives are relatively independent of the torsional-to-vertical frequency ratio for a relatively large range of reduced wind velocities. However, for the model with a relative large gap-width (around 16%), the flutter derivatives are evidently dependent on the frequency ratio for most of the tested reduced velocities. A comparison of the modal d ing ratios also suggests that the torsional d ing ratio is much more sensitive to the frequency ratio, especially for the model with a 16% gap-width. The results of this investigation show that the torsional-to-vertical natural frequency ratio is an important structural parameter, which can significantly affect wind-structure interaction.
Publisher: Elsevier BV
Date: 02-1997
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2012
Publisher: American Society of Civil Engineers (ASCE)
Date: 1992
Publisher: Informa UK Limited
Date: 13-06-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 03-1994
Publisher: Elsevier BV
Date: 12-2014
Publisher: Elsevier BV
Date: 12-1993
Publisher: AIP Publishing
Date: 07-11-2016
DOI: 10.1063/1.4967497
Abstract: This study aims to expand the aeroelastic unstable range of a circular cylinder for improving the efficiency of a vortex-induced vibration (VIV)-based wind energy harvester. The kinetic energy of the harvester is provided by flow-induced vibration of a circular cylinder. Two small-diameter cylindrical rods were attached on two sides of the circular cylinder parallel to the cylinder axis and symmetrical to the stagnation line at a series of circumferential locations. This was inspired by rain-wind-induced vibrations of stay-cables of cable-stayed bridges. It was found that attaching two small-diameter cylindrical rods at the circumferential location θ = 60° significantly expands the aeroelastic unstable range for the circular cylinder. The wind energy harvester with this configuration harnesses the wind energy beyond the VIV onset wind speed and is sustained over the range of wind speed. Therefore, this configuration possesses a dramatic superiority over a plain circular cylinder as the kinetic source of a wind energy harvester.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 08-2010
Publisher: American Society of Civil Engineers (ASCE)
Date: 02-2006
Publisher: Elsevier BV
Date: 2020
Publisher: Elsevier BV
Date: 07-1997
Publisher: Elsevier BV
Date: 09-1993
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 12-1993
Publisher: Elsevier BV
Date: 10-1992
Publisher: Elsevier BV
Date: 2016
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 12-1983
Publisher: Elsevier BV
Date: 08-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 03-1987
Publisher: Elsevier BV
Date: 11-2009
Publisher: Elsevier BV
Date: 08-1990
Publisher: Elsevier BV
Date: 11-1995
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 06-2018
Publisher: Wiley
Date: 25-06-2018
DOI: 10.1002/WE.2219
Publisher: Thomas Telford Ltd.
Date: 08-2016
Abstract: The occupant response to wind-induced building motion is complex, governed by human physiology, and moderated by the psychological response to motion and discomfort within a sophisticated engineered environment. This paper aims to consolidate and critique the early research on the occupant response to building motion and to present recent multidisciplinary research that identifies a broader range of responses to, and consequences of, exposure to building motion. Recent field-based research shows that mild motion sickness, known as sopite syndrome, can cause significantly reduced work performance and occupant comfort. This is supported by laboratory-based physiological studies showing low- litude acceleration induces physiological changes in humans well below the threshold of motion perception (∼6·5 milli-g) which are consistent with the early onset of nausea. Current design criteria, based on perception thresholds, do not include the wider range of possible effects, particularly sopite syndrome and nausea. As a consequence, building occupants may suffer from a range of effects, including sopite syndrome and reduced work performance, that are not considered in current guidelines.
Publisher: Elsevier BV
Date: 07-1997
Publisher: Elsevier BV
Date: 09-2009
Publisher: Research Publishing Services
Date: 2013
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.APERGO.2015.07.010
Abstract: This study uses a longitudinal within-subjects design to investigate the effects of inadequate Indoor Environmental Quality (IEQ) on work performance and wellbeing in a s le of 114 office workers over a period of 8 months. Participants completed a total of 2261 online surveys measuring perceived thermal comfort, lighting comfort and noise annoyance, measures of work performance, and in idual state factors underlying performance and wellbeing. Characterising inadequate aspects of IEQ as environmental stressors, these stress factors can significantly reduce self-reported work performance and objectively measured cognitive performance by between 2.4% and 5.8% in most situations, and by up to 14.8% in rare cases. Environmental stressors act indirectly on work performance by reducing state variables, motivation, tiredness, and distractibility, which support high-functioning work performance. Exposure to environmental stress appears to erode in iduals' resilience, or ability to cope with additional task demands. These results indicate that environmental stress reduces not only the cognitive capacity for work, but the rate of work (i.e. by reducing motivation). Increasing the number of in idual stress factors is associated with a near linear reduction in work performance indicating that environmental stress factors are additive, not multiplicative. Environmental stressors reduce occupant wellbeing (mood, headaches, and feeling 'off') causing indirect reductions in work performance. Improving IEQ will likely produce small but pervasive increases in productivity.
Publisher: Thomas Telford Ltd.
Date: 12-2012
Abstract: The association of bushfires with wind has long been recognised, but the mechanism of this interaction has not received due attention. In the current study, a computational fluid dynamics approach was used to reveal the impact of fire-enhanced wind on low-rise building structures. This paper presents the results of a numerical study on bushfire, wind and structure interactions. The fire-enhanced wind was found to significantly distort the wind velocity profile and enhance turbulence properties, and alter the pressure coefficient distributions around a simple building structure represented by a 6 m cube. In particular, the simulated results revealed a significant increase in windward wall pressure coefficient due to the presence of a fire source upstream compared to that without fire. These findings are expected to have a significant impact on the development of improved design practice for the protection of buildings from fire-induced wind storms.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 04-2015
Publisher: Elsevier BV
Date: 1997
Publisher: Elsevier BV
Date: 03-2019
Publisher: Elsevier BV
Date: 04-1992
Publisher: Elsevier BV
Date: 07-2018
Publisher: Springer Japan
Date: 2013
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 1992
Publisher: Elsevier BV
Date: 11-2012
Publisher: Elsevier BV
Date: 11-1999
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2004
Publisher: SAGE Publications
Date: 06-2007
DOI: 10.1260/136943307781422208
Abstract: This paper describes a proposed wind-excited benchmark tall building incorporating three-dimensional lateral-torsional modes of vibration, which is typical of a significant number of modern tall buildings. A series of wind tunnel pressure tests were conducted on a 1:400 scale model to determine the translational and torsional wind forces acting on the benchmark building. A finite element model was also constructed and mass, d ing, and stiffness matrices were subsequently formulated as an evaluation model for numerical analysis. The evaluation model was further simplified to a state reduced-order system (ROS) using the state order reduction method. A numerical vibration control ex le was conducted to demonstrate the suppression of the wind-induced three-dimensional lateral-torsional motions using a bi-directional tuned mass d er (TMD) incorporating two magnetorheological (MR) d ers, one in each orthogonal direction, to act as a semi-active control system, referred to as a smart tuned mass d er (STMD). The optimal control forces generated by the MR d ers were obtained through the linear quadratic regulator (LQR) to minimize the storey accelerations. The formulation details, methodology and numerical simulation results are outlined in this paper.
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2004
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 1992
Publisher: SAGE Publications
Date: 12-2011
DOI: 10.1260/1369-4332.14.6.1107
Abstract: Field measurement techniques, including ambient wind excitation, crane excitation, synchronised human excitation and mechanical shaker methods, commonly employed to measure the dynamic properties of high-rise buildings are presented. The instrumentation, test methodology, merits and limitations of these techniques, including a purpose-built computer-based mechanical shaker, are discussed. The dynamic properties of four residential buildings in Hong Kong ranging in height from 130 m to 256 m were determined using these field measurement techniques. The results show that the dynamic properties, including natural frequencies of vibration, d ing values, and deflected mode shapes can be accurately determined. These measured dynamic properties are compared with values suggested by wind load standards, empirical predictors and computed values from finite element models. The measured natural frequencies were found to be in good agreement with the Japanese empirical predictor of 67 ided by building height, attributable in part to the design requirements in both regions to resist typhoon loading.
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 02-1994
Publisher: American Physiological Society
Date: 12-2020
Abstract: Little is known about the autonomic consequences of sopite syndrome—the drowsiness that can be induced by low- litude cyclic motion. We recorded skin sympathetic nerve activity (SSNA) in seated participants exposed to slow sinusoidal linear acceleration (0.03–0.2 Hz), which preferentially activates hair cells in the utricular part of the otolithic organs, at litudes that generated no sensations of motion. At all frequencies, there was a clear vestibular modulation of SSNA and cutaneous vasoconstriction.
Publisher: The Hong Kong Institution of Engineers
Date: 2011
Publisher: Elsevier BV
Date: 10-1982
Publisher: Springer Science and Business Media LLC
Date: 15-11-2017
Publisher: Wiley
Date: 17-04-2019
DOI: 10.1002/WE.2346
Publisher: Springer Science and Business Media LLC
Date: 02-07-2018
DOI: 10.1007/S00221-018-5323-2
Abstract: We tested the hypothesis that random variations in the magnitude of sinusoidal linear acceleration cause greater modulation of skin sympathetic nerve activity (SSNA), but not muscle sympathetic nerve activity (MSNA), than sinusoidal stimuli of the same frequency but constant litude. Subjects (n = 22) were seated in a sealed room mounted on a linear motor that could deliver peak sinusoidal accelerations of 30 mG in the antero-posterior direction. Subjects sat on a padded chair with their neck and head supported vertically, thereby minimizing somatosensory cues, facing the direction of motion in the anterior direction. Each block of sinusoidal motion was delivered at 0.2 Hz, either with a constant- litude (root mean square 14 mG) or randomly fluctuating litudes of the same mean litude. MSNA (n = 12) and SSNA (n = 10) were recorded via tungsten microelectrodes inserted into muscle or cutaneous fascicles of the common peroneal nerve. Cross-correlation analysis was used to measure the magnitude of vestibular modulation. The modulation index for SSNA was significantly higher during delivery of random vs constant- litude acceleration (31.4 ± 1.9 vs 24.5 ± 2.5%), but there was no significant difference in the modulation indices for MSNA (28.8 ± 2.9 vs 33.4 ± 4.1%). We conclude that the pattern of vestibular stimulation affects the magnitude of modulation of sympathetic outflow to skin but not to muscle. Presumably, this is related to the subperceptual development of nausea, which is known to be associated with greater vestibular modulation of SSNA but not MSNA.
Publisher: Elsevier BV
Date: 12-1985
Publisher: Elsevier BV
Date: 02-2021
Publisher: Springer Science and Business Media LLC
Date: 27-12-2013
Publisher: Elsevier BV
Date: 08-2019
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 2022
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2009
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 04-1996
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 11-1995
Publisher: Zhejiang University Press
Date: 2012
Publisher: Elsevier BV
Date: 12-2002
Publisher: Springer Japan
Date: 2013
Publisher: Elsevier BV
Date: 04-1999
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 02-1997
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 09-2017
Publisher: Elsevier BV
Date: 03-2015
Publisher: AIP Publishing
Date: 27-11-2017
DOI: 10.1063/1.5008918
Abstract: This study examines effects of the splitter plate placed in the near wake of a circular cylinder on the performance of a piezoelectric wind energy harvester through wind tunnel experiments. The kinetic energy of the harvester is gained by wind-induced vibrations of the circular cylinder. The splitter plate is attached to the leeward side of the cylinder. The ratio of the splitter plate length to the diameter of the circular cylinder (Lsp/D) ranges from 0.25 to 2.00. After attaching the splitter plate with an appropriate length, the harvester is able to sustain large litude vibrations beyond the wind speed range corresponding to vortex-induced vibrations. Thus, the upper bound of the wind speed range for the harvester to harness wind energy is eliminated, which significantly increases the efficiency of the harvester. Compared to the different lengths of the splitter plate, 0.65D has been found to be the optimal length for maximizing the harvested power.
Publisher: Elsevier BV
Date: 09-2018
Publisher: International Association for Fire Safety Science
Date: 2011
Publisher: Elsevier BV
Date: 05-1990
Publisher: Springer Science and Business Media LLC
Date: 14-07-2013
DOI: 10.1007/S00221-013-3637-7
Abstract: We recently showed that selective stimulation of one set of otolithic organs-those located in the utricle, sensitive to displacement in the horizontal axis-causes a marked entrainment of skin sympathetic nerve activity (SSNA). Here, we assessed whether muscle sympathetic nerve activity (MSNA) is similarly modulated. MSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in 12 awake subjects, seated (head vertical, eyes closed) on a motorised platform. Slow sinusoidal accelerations-decelerations (±4 mG) were applied in the X (antero-posterior) or Y (medio-lateral) direction at 0.08 Hz. Cross-correlation analysis revealed partial entrainment of MSNA: vestibular modulation was 32 ± 3 % for displacements in the X-axis and 29 ± 3 % in the Y-axis these were significantly smaller than those evoked in SSNA (97 ± 3 and 91 ± 5 %, respectively). For each sinusoidal cycle, there were two peaks of modulation-one associated with acceleration as the platform moved forward or to the side and one associated with acceleration in the opposite direction. We believe the two peaks reflect inertial displacement of the stereocilia within the utricle during sinusoidal acceleration, which evokes vestibulosympathetic reflexes that are expressed as vestibular modulation of MSNA as well as of SSNA. The smaller vestibular modulation of MSNA can be explained by the dominant modulation of MSNA by the arterial baroreceptors.
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 11-2001
Publisher: Elsevier BV
Date: 10-1992
Publisher: Research Publishing Services
Date: 2013
Publisher: Elsevier BV
Date: 05-2002
Publisher: Wiley
Date: 06-03-2019
DOI: 10.1002/ESE3.300
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2004
Publisher: Elsevier BV
Date: 10-1997
Publisher: Elsevier BV
Date: 11-2017
Publisher: Elsevier BV
Date: 06-2005
Publisher: Frontiers Media SA
Date: 09-10-2014
Publisher: SAGE Publications
Date: 06-2011
DOI: 10.1260/1369-4332.14.3.489
Abstract: There have been significant development of techniques for determining optimum parameters of passive d ers and vibration absorbers, but most of the existing studies are limited to the case of an und ed primary structure. This paper aims to develop a first order approximation of the optimal liquid column vibration absorber (LCVA) parameters for suppressing the displacement response of a d ed structure under white noise induced ground acceleration. The optimum parameters of a LCVA for the case of an und ed primary structure subjected to white noise induced ground acceleration are first derived and the results are then extended to the case where some d ing exists in the primary structure by using a perturbation technique. The accuracy of the derived formulas is then verified through a comparison with the results obtained from numerical methods as well as the results of other studies found in the literature. Finally, a direct approach for determining the optimal head loss coefficient is presented in this study. It is demonstrated that the closed-form approach is capable of predicting the optimal liquid column vibration absorber parameters with reasonable accuracy for d ed primary structure.
Publisher: AIP Publishing
Date: 12-08-2019
DOI: 10.1063/1.5109457
Abstract: This study evaluated the performance of twin adjacent galloping-based piezoelectric wind energy harvesters based on mutual interference. The relative position between the twin harvesters is crucial to their energy generation efficiency. A series of wind tunnel tests were conducted to test energy generation of the two harvesters in tandem or staggered arrangements. The optimal relative position, a streamwise center to center spacing of 1.2B (B is the width of the harvester's square prism) and a transverse center to center spacing of 1.0B, was identified. The total output power of the two harvesters placed in the optimal relative position is up to 2.2 times that of two isolated harvesters. The output power is also much larger than that of the harvesters in tandem arrangements that have been widely tested in previous studies. Therefore, it is recommended to position two adjacent harvesters in optimal relative position(s) to deliver an optimal power output.
Publisher: Elsevier BV
Date: 05-2001
Publisher: Elsevier BV
Date: 12-2004
Publisher: Elsevier BV
Date: 12-2019
Publisher: Elsevier BV
Date: 03-2018
Publisher: Elsevier BV
Date: 08-1988
Publisher: Elsevier BV
Date: 06-1997
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2009
Publisher: Springer Singapore
Date: 04-09-2020
Publisher: Elsevier BV
Date: 1992
Publisher: Elsevier BV
Date: 06-1995
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 07-2015
Publisher: Elsevier BV
Date: 05-2010
Publisher: Elsevier BV
Date: 1992
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 04-2018
Publisher: Elsevier BV
Date: 02-2016
Publisher: Elsevier BV
Date: 07-1997
Publisher: American Society of Civil Engineers (ASCE)
Date: 11-1984
Publisher: Elsevier BV
Date: 04-1988
Publisher: Elsevier BV
Date: 12-1922
Publisher: SAGE Publications
Date: 04-2006
DOI: 10.1260/136943306776986994
Abstract: A series of wind tunnel tests were carried out to measure drag and lift coefficients of inclined circular cylinders with artificial rivulet for later investigation on wind-rain-induced cable vibration. The axial flow effect was naturally included in the tests, compared with previous non-yawed horizontal cylinder tests. The test Reynolds number for smooth circular cylinders in uniform flow ranged from 9.38 × 10 4 to 1.93 × 10 5 . A special test apparatus was designed and manufactured for easy execution of measurements. The effects of artificial rivulet, its shape, and its size on aerodynamic coefficients are discussed in this paper based on wind tunnel test results. The influence of wind yaw angle, wind speed, and cable diameter is also estimated. Furthermore, the possible transformation of wind tunnel test results to the cylinders of different inclinations and yaw angles from those used in the tests is explored.
Publisher: Informa UK Limited
Date: 2015
Publisher: Informa UK Limited
Date: 09-1980
Publisher: ASME International
Date: 06-1983
DOI: 10.1115/1.3240953
Abstract: When a prismatic structure is subjected to air flow, especially at small angle of wind incidence, the separated shear layers may reattach onto the streamwise surface. The turbulent mixing in the shear layers and the extrainment of fluid results in highly fluctuating and strongly negative pressures under the reattaching shear layers. Wind tunnel tests were carried out to determine the pressure distribution around a square cylinder. It was found that an increase in turbulence, in particular fine scale turbulence, significantly altered the pressure distribution, the transverse force characteristic, and hence the galloping behavior of the square cylinder. When small vanes were fitted to the corners of the cylinder, and by maintaining a vent between the vane and the corner, the magnitude of the negative mean and peak pressure coefficients under the shear layer were substantially reduced.
Publisher: Elsevier BV
Date: 03-2016
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 04-2013
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 03-1996
Publisher: Frontiers Media SA
Date: 16-02-2016
Publisher: Elsevier BV
Date: 07-2019
Publisher: Elsevier BV
Date: 11-2018
Publisher: Elsevier BV
Date: 06-2020
Publisher: ASME International
Date: 03-09-2016
DOI: 10.1115/1.4031257
Abstract: Vortex-induced vibration (VIV) of two rigidly connected circular cylinders in side-by-side and tandem arrangements in the cross-flow direction was investigated using two-dimensional (2D) numerical simulations. The 2D Reynolds-Averaged Navier–Stokes (RANS) equations were solved for the flow, and the equation of the motion was solved for the response of the cylinders. Simulations were conducted for a constant mass ratio of 2.5, gap ratios G (ratio of the gap between the cylinders to the cylinder diameter) in the range of 0.5 to 3, and reduced velocities in the range of 1 to 30. The effects of the gap ratio on the response of the cylinders were analyzed extensively. The maximum response litude in the lock-in regime was found to occur at G = 0.5 in the side-by-side arrangement, which is about twice that of a single cylinder. In the side-by-side arrangement, the response regime of the cylinders for gap ratios of 1.5, 2, 2.5, and 3 is much narrower than that of a single cylinder, because the vortex shedding from the two cylinders is in an out-of-phase pattern at large reduced velocities. In the tandem arrangement, the maximum response litude of the cylinders is greater than that of a single cylinder for all the calculated gap ratios. For the gap ratio of 0.5 in the tandem arrangement, the vortex shedding frequency from the upstream cylinder was not observed in the vibration at large reduced velocities, and the response is galloping.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2020
Publisher: Elsevier BV
Date: 08-2018
Publisher: Wiley
Date: 04-2011
DOI: 10.1002/TAL.620
Publisher: Elsevier BV
Date: 03-2012
Publisher: Elsevier BV
Date: 02-1995
Publisher: Springer Science and Business Media LLC
Date: 07-02-2014
DOI: 10.1007/S00221-014-3856-6
Abstract: We assessed the capacity for the vestibular utricle to modulate muscle sympathetic nerve activity (MSNA) during sinusoidal linear acceleration at litudes extending from imperceptible to clearly perceptible. Subjects (n = 16) were seated in a sealed room, eliminating visual cues, mounted on a linear motor that could deliver peak sinusoidal accelerations of 30 mG in the antero-posterior direction. Subjects sat on a padded chair with their neck and head supported vertically, thereby minimizing somatosensory cues, facing the direction of motion in the anterior direction. Each block of sinusoidal motion was applied at a time unknown to subjects and in a random order of litudes (1.25, 2.5, 5, 10, 20 and 30 mG), at a constant frequency of 0.2 Hz. MSNA was recorded via tungsten microelectrodes inserted into muscle fascicles of the common peroneal nerve. Subjects used a linear potentiometer aligned to the axis of motion to indicate any perceived movement, which was compared with the accelerometer signal of actual room movement. On average, 67% correct detection of movement did not occur until 6.5 mG, with correct knowledge of the direction of movement at ~10 mG. Cross-correlation analysis revealed potent sinusoidal modulation of MSNA even at accelerations subjects could not perceive (1.25-5 mG). The modulation index showed a positive linear increase with acceleration litude, such that the modulation was significantly higher (25.3 ± 3.7%) at 30 mG than at 1.25 mG (15.5 ± 1.2%). We conclude that selective activation of the vestibular utricle causes a pronounced modulation of MSNA, even at levels well below perceptual threshold, and provides further evidence in support of the importance of vestibulosympathetic reflexes in human cardiovascular control.
Publisher: Elsevier BV
Date: 08-2018
Publisher: American Society of Civil Engineers (ASCE)
Date: 04-2004
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 07-1990
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 02-1995
Publisher: Elsevier BV
Date: 03-2020
Publisher: China Science Publishing & Media Ltd.
Date: 13-06-2012
Publisher: Elsevier BV
Date: 12-2016
No related grants have been discovered for Kenny Kwok.