We have studied the effects of local topography and canopy structure on turbulent flux measurements at a site located in mountainous terrain within a subalpine, coniferous forest. Our primary aim was to determine whether the complex terrain of the site affects the accuracy of eddy flux measurements from a practical perspective. We observed displacement heights, roughness lengths, spectral peaks...

in this work we solve the set of hydrodynamical equations for accretion disks in the spherical coordinates (r,θ,ϕ) to obtain the explicit structure along θ direction. we study a two-dimensional advective accretion disc in the presence of thermal conduction. we find self-similar solutions for an axisymmetric, rotating, steady, viscous-resistive disk. we show that the global structure of an advec...

Accurate prediction of advection and turbulent mixing is fundamental to understanding the transport and deposition of atmospheric pollutants. There is mounting evidence hinting at overestimation of wind speed in the urban airshed by conventional mesoscale NWP models. This has been hypothesized as a factor contributing to air quality models underestimating pollutant concentrations in highly urba...

In our present research, we focus on the modeling of airflow related to natural disasters, such assand accumulation, with urban form studies. The objective is to find which urban form can promote sand passing andreduce as much as possible stagnation of sand in the building area (streets, alleys, etc.). The urban form design will bediscussed through the simulation of airflow by using Computation...

Flooding in urban areas is an inevitable problem for many cities in Asia. In Bangladesh, Dhaka has serious problems related to urban flooding. The situation was highlighted in September 1996 when residences experienced ankle to kneedeep water on the streets. Daily activities in parts of the city were nearly paralyzed and heavy traffic jams occurred due to stagnant water on the streets. The stud...

In this work we solve the set of hydrodynamical equations for accretion disks in the spherical coordinates (r,θ,ϕ) to obtain the explicit structure along θ direction. We study a two-dimensional advective accretion disc in the presence of thermal conduction. We find self-similar solutions for an axisymmetric, rotating, steady, viscous-resistive disk. We show that the global structure of an advec...

Due to the complexity of built environment, urban design patterns considerably affect the microclimate and outdoor thermal comfort in a given urban morphology. Variables such as building heights and orientations, spaces between buildings, plot coverage alter solar access, wind speed and direction at street level. To improve microclimate and comfort conditions urban design elements including veg...

Currently there are few observations of the urban wind field at heights other than rooftop level. Remote sensing instruments such as Doppler lidars provide wind speed data at many heights, which would be useful in determining wind loadings of tall buildings, and predicting local air quality. Studies comparing remote sensing with traditional anemometers carried out in flat, homogeneous terrain o...

Dense urban areas restrict air movement, causing airflow in urban street canyons to be much lower than the flow above buildings. Boosting near-ground wind speed can enhance thermal comfort in warm climates by increasing skin convective heat transfer. We explored the potential of a wind catcher to direct atmospheric wind into urban street canyons. We arranged scaled-down models of buildings with...

the urban heat island effect refers to the temperature rise of the cities in comparison to the suburbs. this phenomenon which is a consequence of urbanization and has become a major issue in the urban climatology may have serious consequences in the developing countries which are facing a rapid and unplanned urban growth. tehran, the capital and the most populated city of iran, this phenomenon ...