46 research outputs found

    Wind loads and their reduction on mesh fabrics

    Get PDF
    The presented contribution deals with evaluation of wind loads on various layouts of plastic and steel mesh fabric. To obtain real wind effects and loads, the experimental measurement in the Boundary Layer Wind Tunnel (BLWT) in Bratislava has been prepared. The goal of an investigation is the determination of wind loads on permeable materials – plastic and steel fabric, using wind load reduction factor k. The mean wind pressure on the permeable material is obtained by multiplying the wind pressure to the impermeable surface by the reduction factor k depending on the Reynolds number. The experimentally determined reduction factor can be applied for design of the safety mesh fabric. Wind loads were obtained from measurement of wind velocity by Hot-Wire anemometry (HWA)

    Functional aerodynamics and its influence on the energy and thermal mode of a naturally ventilated double-skin transparent façade

    Get PDF
    This article deals with the dynamics of airflow through a cavity. In windless conditions, where a natural flow causes the flow of air in the cavity, the overall aerodynamic resistance of the cavity is the important aerodynamic parameter, which is the sum of the local resistances alongside the air movement trajectory through the cavity. The total aerodynamic resistance of the cavity must be lesses than the force of the convective buoyancy of the air in the cavity. The following conclusions were found experimentally. The convection occurs in the cavity at every time step with a velocity range from 0.05 ≤ v [m/s] ≤ 0.2 to 0.3. The energy regime in the cavity is characterised by inhomogeneity. In the cavity, there are zones of increasing temperatures along the height of the cavity at the inlet. A large area with increased temperatures at the air outlet and a small area with particularly high temperatures in the upper part of the inlet were found

    Proceedings of the 12th International Conference on Kinanthropology

    Get PDF
    Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

    Get PDF
    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049

    Experimental determination of wind action on triangular solar panel assemblies

    No full text
    The article deals with aerodynamic study of solar panel assemblies. Experimental measurements were realized in BLWT wind tunnel. The aim of the solution was to determine the maximum pressure and suction wind load on top and bottom surfaces of panels. The resulting net pressure coefficient represents the maximum local pressure in each panel row as maximum values from all wind directions. The experimentally obtained cp,net values were compared with the conservative values in EN 1991-1-4 for open monopitch canopies. A lower wind load in the inner regions of the triangular assemblies should be used in the design of fixing supports

    Experimental determination of wind action on triangular solar panel assemblies

    Get PDF
    The article deals with aerodynamic study of solar panel assemblies. Experimental measurements were realized in BLWT wind tunnel. The aim of the solution was to determine the maximum pressure and suction wind load on top and bottom surfaces of panels. The resulting net pressure coefficient represents the maximum local pressure in each panel row as maximum values from all wind directions. The experimentally obtained cp,net values were compared with the conservative values in EN 1991-1-4 for open monopitch canopies. A lower wind load in the inner regions of the triangular assemblies should be used in the design of fixing supports

    Distribution of the external pressure coefficients on the elliptic tower: experimental measurement compared with numerical modelling

    No full text
    The wind flow around the elliptical object was investigated experimentally in the BLWT wind tunnel in Bratislava and subsequently solved by computer wind flow simulation. On a high-rise building model, the external wind pressure coefficients were evaluated for different wind directions and then compared with the numerical CFD simulation in ANSYS, where different models of turbulence and mesh types were used. The aim of the article was to evaluate and compare the obtained values and after analysing the results to choose the most suitable model of turbulence and mesh types, which showed the smallest deviations from the experimental values

    Implementation of Data from Wind Tunnel Tests in the Design of a Tall Building with an Elliptic Ground Plan

    No full text
    The design of a 69 m tall multipurpose building was investigated in this paper. The shape of the structure above the ground was an elliptical cylinder. Under the ground, the building was extended into a cuboid shape (for car parking). External wind pressure coefficients were determined using three methods: wind tunnel tests, CFD, and “the simplification of the shape” (using information defined in building standards). From the obtained results, it was evident that the simplification did not provide results with sufficient accuracy. The external wind pressure coefficients presented in this paper should be used for the design of a similar structure. The shape of the elliptical cylinder is very sensitive to applied wind. Positive pressures only occur on a small area of the windward side. The rest of the windward side is loaded with negative pressures. Therefore, torsional effects can occur, and these can be dangerous for the structure. The leeward side is completely loaded with negative pressures. In our case, this information was necessary for a follow-on static and dynamic analysis of the building. Various subsoil stiffness coefficients were considered. The calculated horizontal displacement was compared with the limit value. A measured wind direction of 20° caused the maximum obtained torsional moment, and a wind direction of 90° induced the maximum obtained force. The commercial program Ansys Fluent 2022 was used for the CFD simulation. The SCIA ENGINEER 21 program was used for follow-on analysis. This paper presents brief information on the selected turbulence model and details the settings used for the CFD simulation. Also, a description of the wind tunnel laboratory utilized in this study is provided, along with a description of the measuring devices used and the methodologies of the tests carried out. The main purpose of this paper is to show how important it is to consider the wind load for the static analysis of a structure like this

    Numerical Analysis of Wind Effects on a Residential Building with a Focus on the Linings, Window Sills, and Lintel

    No full text
    This article deals with the investigation of wind effects on a façade of a rectangular residential building with explicit modelling of the windows for specific wind conditions. The external wind pressure coefficients were treated on the façade and at the places of the window sills, linings, and lintel for the direction of the wind from 0° to 90° with increments of 22.5°. For a detailed analysis, the CFD simulation using Ansys Fluent was used. The method selected for the CFD simulation solution and its setting (quality of meshing, horizontal homogeneity of the boundary layer, etc.) were verified by known results of similar objects. The purpose of this analysis is to show how important it is to consider wind effects to determine the suitable placement of passive ventilation devices. Research shows the potential optimal position of ventilation units in terms of favourable pressure distribution. Zones with negative pressure and corners or façades in a wake are not suitable for applying passive ventilation units. The results can serve as a basis for designers to achieve optimal comfort in residential buildings
    corecore