Study On Architectural Models Designed For Natural Ventilation By Finite Element Method

With people's health status according to statistics getting worse and worse, improving the quality of health is an inevitable need that many researchers are interested in. In addition to improving through eating, improving the living environment in homes and workplaces is also essential. Nowadays, many countries around the world have implemented many house models that apply natural ventilation instead of artificial air conditioning system, because natural wind is better and also feels more comfortable. Therefore, the study of controlled natural wind-catching architecture is necessary and consistent. Research in this field can help improve the living environment for people. The objective of the paper is to simulate ventilation solutions based on experience in construction works by finite volume method through ANSYS software to consider and evaluate the feasibility of these solutions. If the simulation results match or approximate the actual verified results, they can be applied to the improvement of natural ventilation structures to create a better indoor living environment, meeting the requirements of the environment. more comfortable diagnostics.

DESIGN AND TEST OF SELF-PROPELLED STRADDLE-TYPE LYCIUM BARBARUM L. SPRAYING MACHINE

According to the planting agronomy of Lycium barbarum L. in Ningxia, a self-propelled straddle-type sprayer was designed. The aim was to reduce the labor requirements, improve the spraying effect to the middle and lower parts of the canopy, reduce the influence of natural wind on droplet drift, and recycle excess liquid medicine to reduce environmental pollution. Tests showed that the coverage rate of liquid medicine on the leaf surface and back of the leaf peaked at 84.2% and 48.3%, respectively, when spraying pressure was high. Under different spraying distances, the coverage rate of liquid medicine on leaf surface and back of leaf reached 73.3% and 38.3% at the shortest distance. The uniformity of the spray droplet distribution was good, the use error was less than 10%, and the excess liquid was effectively recovered.

Effect of Natural Wind on the Transiting Test for Measuring the Aerodynamic Coefficients of Structures

The aerodynamic coefficients transiting test is a new method for measuring the structural aerodynamic coefficients using the wind generated by a moving vehicle. However, the effect and correction of natural wind on the transiting test has not been studied. Hence, in this study, the investigation of the aerodynamic force and pressure measurements on a special triangular prism model is simulated through the transiting test under different natural wind conditions for 30° and 90° angles of wind incidence. Force and pressure measurement results in the transiting test are used to describe and explain the effect of natural wind in the range of 0–3.0 m/s on the aerodynamic coefficients of the triangular prism qualitatively and quantitatively. The results show that the driving wind field of the vehicle, aerodynamic force coefficient, and aerodynamic pressure coefficient are significantly influenced by strong natural wind greater than 1.71 m/s, which must be considered and so it is recommended that the structure aerodynamic coefficients transiting test should be conducted under the condition that the natural wind is less than 1.71 m/s. In addition, the method of two-direction round-trip measurement is proposed to modify the effect of natural wind on transiting tests.

Applications of the Atmospheric Transport and Diffusion of LES Modeling to the Spread and Dissipation of COVID-19 Aerosol Particles inside and outside the Japan National Stadium (Tokyo Olympic Stadium)

In this paper, we use an analysis function for gas diffusion known as the Research Institute for Applied Mechanics, Kyushu University, Computational Prediction of Airflow over Complex Terrain (RIAM-COMPACT), which was developed for complex terrain, in Airflow Analyst software, and apply it to the spread and dissipation of a fluid layer (assuming the fluid layer contains COVID-19 particles). First, to verify the prediction accuracy of the gas diffusion using RIAM-COMPACT, comparisons with past wind tunnel test results conducted on simple and complex terrains are presented under neutral atmospheric stability. The results of the numerical simulations carried out in this study show good agreement with the wind tunnel experiments for both simple and complex terrains. Next, a model of the Japan National Stadium (Tokyo Olympic Stadium) was constructed using 3D detailed topographic Advanced World 3D Map (AW3D) data generated by combining high-resolution satellite images. We tried to reproduce the hypothetical spread and dissipation of the fluid layer (assuming the fluid layer contains COVID-19 particles) inside and outside of the Japan National Stadium using Airflow Analyst implemented with the RIAM-COMPACT analysis function for gas diffusion. We paid special attention to the effect of wind ventilation driven by natural wind. The numerical results under various scenarios show that ventilation driven by natural wind is very effective for the Japan National Stadium.

The Occurrence of Skeletons of Silicoflagellata and Other Siliceous Bioparticles in Floral Honeys

Siliceous marine microfossils were unexpectedly discovered during the analysis of flower honey samples from Poland and Tunisia. The microfossils were represented by protist with siliceous skeletons: silicoflagellates, diatoms, and endoskeletal dinoflagellates. This is the first record of such microfossils in honeys. Based on the high percent of anemophilous pollen grains and spores in the sample, it was hypothesized that silicoflagellates were deposited from the air onto the nectariferous flowers, then bees harvested them with the nectar. Based on the comparison of pollen content of honeys and flowering calendar of Tunisia, the harvest time of honey was identified as a period between 1 April and 31 May 2011. Trajectory analysis of air masses in this period confirmed that siliceous microfossils could be aerosolized by wind from the rocks of the so-called Tripoli Formation of Messinian age (6–7 Ma). Similar to the Tunisian case, the Polish trajectory simulation also supports the hypothesis of atmospheric transport of silicoflagellates from outcrops of Oligocene age in the Polish Outer Carpathians. In the case of diatom content of honey, however, the source can be both natural (wind) and artificial (diatomaceous earth filters). For a correct determination, natural sources of siliceous bioparticles, such as wind transport from nearby outcrops should be also considered. Silicoflagellates could be used as complementary indicators of the geographical origin of honeys collected in areas characterized by diatomite outcrops, supporting the results obtained with other methods; thus, such indicators merit further studies within the area of honey authenticity.