22 papers · ranked by Valyu relevance
T. Petäjä, L. Järvi, V.-M. Kerminen, A.J. Ding + 8 more
'J. Kujansuu' 'A. Virkkula' 'X. Yang' 'C.B. Fu' 'S. Zilitinkevich' 'M. Kulmala'] Severe air pollution episodes have been frequent in China during the recent years. While high emissions are the primary reason for increasing pollutant concentrations, the ultimate cause for the most severe pollution episodes has remained…
Deepak Kumar Kar, Chirag Mahida
The summer internship at the Physical Research Laboratory (PRL), Ahmedabad, under the Department of Space and Atmospheric Sciences, provided a unique and invaluable learning opportunity. This experience has not only broadened our academic horizons but also allowed usto apply theoretical knowledge to practical research…
N. Karjanto
This article covers a concise review of the planetary boundary layer (PBL). This part of the atmosphere should be of particular interest to many of us. Since we live within the PBL, our lives and those of vegetation and animals, flora and fauna, are directly influenced by what is happening here. From the moment of our…
Philip E. Hancock, Paul Hayden
The simulation of horizontally homogeneous boundary layers that have characteristics of weakly and moderately stable atmospheric flow is investigated, where the well-established wind engineering practice of using ‘flow generators’ to provide a deep boundary layer is employed. Primary attention is given to the flow…
Mikko Folkersma, Roland Schmehl, Axelle Viré
We present a computational fluid dynamic analysis of boundary layer transition on leading edge inflatable kite airfoils used for airborne wind energy generation. Because of the operation in pumping cycles, the airfoil is generally subject to a wide range of Reynolds numbers. The analysis is based on the combination of…
Jainagesh A. Sekhar, Leonid M. Martyushev
A postulate that relates global warming to higher entropy generation rate demand in the tropospheric is offered and tested. This article introduces a low-complexity model to calculate the entropy generation rate required in the troposphere. The entropy generation rate per unit volume is noted to be proportional to the…
Kedar C. Chitale, Michel Rasquin, Onkar Sahni, Mark S. Shephard + 1 more
'Kenneth E. Jansen'] Abstract. Boundary layers in turbulent flows require fine grid spacings near the walls which depend on the choice of turbulence model. To satisfy these requirements a semistructured mesh is generally used in this area with orthogonal and layered elements. Adaptation of such a mesh needs to take…
Gabriel Y. R. Hamada, William R. Wolf, Hugo F. S. Lui, Carlos Junqueira-Junior
Boundary layers of adiabatic and isothermal curved walls are investigated for a supersonic turbine cascade, including the effects of shock-boundary layer interactions (SBLIs). Wall-resolved large eddy simulations (LES) are performed for a linear cascade of blades with an inlet Mach number of ∞ = 2.0 and Reynolds number…
Camilla W. Stjern, Øivind Hodnebrog, Gunnar Myhre, Ignacio Pisso
Ventilation of health hazardous aerosol pollution within the planetary boundary layer (PBL) - the lowest layer of the atmosphere - is dependent upon turbulent mixing, which again is closely linked to the height of the PBL. Here we show that emissions of both CO2 and absorbing aerosols such as black carbon influence the…
Or Shapira, Uri Hochberg, Scott McAdam, Tamar Azoulay-Shemer + 3 more
Understanding the relationship between wind speed and gas exchange in plants is a longstanding challenge. Our aim was to investigate the impact of wind speed on maximum rates of gas exchange and the kinetics of stomatal responses. We conducted experiments using an infrared gas analyzer equipped with a controlled leaf…
Mads Lichtenberg, Rasmus Dyrmose Nøerregaard, Michael Kühl
The role of hyaline hairs on the thallus of brown-algae in the genus Fucus is long debated and several functions have been proposed. We used a novel motorized setup for 2D-and 3D-mapping with O_2_-microsensors to investigate the spatial heterogeneity of the diffusive boundary layer (DBL) and O_2_ flux around single and…
Zhenqing Wang, Mingfang Shi, Xiaojun Tang, Hongqing Lv + 1 more
A high-order finite difference method was used to simulate the hypersonic flow field over a blunt cone with different height roughness elements. The unsteady flow field induced by pulse disturbances was analyzed and compared with that under continuous disturbances. The temporal and spatial evolution characteristics of…
Teresa Lo Feudo, Claudia Roberta Calidonna, Elenio Avolio, Anna Maria Sempreviva
'Anna Maria Sempreviva'] The understanding of the atmospheric processes in coastal areas requires the availability of quality datasets describing the vertical and horizontal spatial structure of the Atmospheric Boundary Layer (ABL) on either side of the coastline. High-resolution Numerical Weather Prediction (NWP)…
Klaus Petschel, S. Stellmach, Michael Wilczek, Johannes Lülff + 1 more
'Ulrich Hansen'] Boundary layers play an important role in controlling convective heat transfer. Their nature varies considerably between different application areas characterized by different boundary conditions, which hampers a uniform treatment. Here, we argue that, independent of boundary conditions, systematic…
I. Pajic-Lijakovic, M. Milivojevic
Stress generation during collective cell migration represents one of the key factors which influence the configuration of migrating cells, viscoelasticity of multicellular systems and their inter-relation. Local generation of stress (normal and shear) is significant even in 2D (up to ~100 − 150 Pa). Compressive stress…
Martin Kutscherauer, Scott Anderson, Sebastian Böcklein, Gerhard Mestl + 2 more
Modeling catalytic fixed bed reactors with a small tube-to-particle diameter ratio requires a detailed description of the interactions between fluid flow, intra-particle transport, and the chemical reaction(s) within the catalyst. Particle-resolved computational fluid dynamics (PRCFD) simulations are the most promising…
Douglas Barlow, Fenner Colson
Recently, molecular dynamics simulations have predicted that concentric layers of gaseous carbon dioxide particles will appear in carbon nanotubes. We show in this letter how this effect can be predicted analytically by considering the potential field generated by the pore wall. The layer potential expression thus…
Maitreyee Sharma Priyadarshini, Richard Jaffe, Marco Panesi
This paper studies the thermochemistry and electronic structure of small carbon clusters and hydrocarbons which are major constituents of pyrolysis gases released into the boundary layer of ablating heat shields. Our focus lies on clusters of up to four carbon atoms including C3H and C4H. A study of electronically…
Alberto Padovan, Blaine Vollmer, Francesco Panerai, Marco Panesi + 2 more
'Kelly A. Stephani' 'Daniel J. Bodony'] The B′ formulation can be understood as a mass and energy conservation formalism at a reacting singular surface. In hypersonics applications, it is typically used to compute the chemical equilibrium properties of gaseous mixtures at ablating surfaces, and to estimate the…
utiyama masahiro, fukuyama tsutom
Formation and growth of water droplets were studied using a semi-real scale experimental system; the main component of the system was a 430 m vertical shaft used to perform cloud formation experiments at a spatial scale close to that of the real atmosphere. By generating an updraft with humid air, a cloud was observed…
Florence K. A. Gregson, Nealan G. A. Gerrebos, Meredith Schervish, Sepehr Nikkho + 7 more
Smoke particles generated by burning biomass consist mainly of organic aerosol, referred to as biomass-burning organic aerosol (BBOA). BBOA influences the climate by scattering and absorbing solar radiation or acting as nuclei for cloud formation. The viscosity and the phase behavior (i.e. the number and type of phases…
Gabriel C. Mel, Chaithanya A. Ramachandra, Bartlett W. Mel
Detecting object boundaries is crucial for recognition, but how the process unfolds in visual cortex remains unknown. To study the problem faced by a hypothetical boundary cell, and to predict how cortical circuitry could produce a boundary cell from a population of conventional “simple cells”, we labeled 30,000…