scholarly journals Coastal Boundary Layer Characteristics of Wind, Turbulence, and Surface Roughness Parameter over the Thumba Equatorial Rocket Launching Station, India

2014 ◽  
Vol 2014 ◽  
pp. 1-21 ◽  
Author(s):  
K. V. S. Namboodiri ◽  
Dileep Puthillam Krishnan ◽  
Rahul Karunakaran Nileshwar ◽  
Koshy Mammen ◽  
Nadimpally Kiran kumar
Keyword(s):  
Boundary Layer ◽  
Surface Roughness ◽  
Wind Direction ◽  
Roughness Parameter ◽  
Turbulent Heat ◽  
Surface Roughness Parameter ◽  
South West Monsoon ◽  
Wind Turbulence ◽  
Coastal Boundary Layer ◽  
Coastal Boundary

The study discusses the features of wind, turbulence, and surface roughness parameter over the coastal boundary layer of the Peninsular Indian Station, Thumba Equatorial Rocket Launching Station (TERLS). Every 5 min measurements from an ultrasonic anemometer at 3.3 m agl from May 2007 to December 2012 are used for this work. Symmetries in mesoscale turbulence, stress off-wind angle computations, structure of scalar wind, resultant wind direction, momentum flux (M), Obukhov length (L), frictional velocity (u*), w-component, turbulent heat flux (H), drag coefficient (CD), turbulent intensities, standard deviation of wind directions (σθ), wind steadiness factor-σθ relationship, bivariate normal distribution (BND) wind model, surface roughness parameter (z0), z0 and wind direction (θ) relationship, and variation of z0 with the Indian South West monsoon activity are discussed.

scholarly journals On the photochemical production of new particles in the coastal boundary layer

1999 ◽  
Vol 26 (12) ◽  
pp. 1707-1710 ◽  
Author(s):  
Colin O'Dowd ◽  
Gordon McFiggans ◽  
David J. Creasey ◽  
Liisa Pirjola ◽  
Claudia Hoell ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Photochemical Production ◽  
Coastal Boundary Layer ◽  
Coastal Boundary ◽  
New Particles

Observations of atmospheric trace gases by MAX-DOAS in the coastal boundary layer over Jiaozhou Bay

2014 ◽  
Author(s):  
Xianxin Li ◽  
Zhangjun Wang ◽  
Xiangqian Meng ◽  
Haijin Zhou ◽  
Libin Du ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Trace Gases ◽  
Jiaozhou Bay ◽  
Atmospheric Trace Gases ◽  
Coastal Boundary Layer ◽  
Coastal Boundary

Sea Spray Effects on Marine and Coastal Boundary Layer

2019 ◽  
pp. 389-393
Author(s):  
George Kallos ◽  
C. Stathopoulos ◽  
P. Patlakas ◽  
G. Galanis ◽  
J. Al Qahtani ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Sea Spray ◽  
Coastal Boundary Layer ◽  
Coastal Boundary

Surface Roughness at Wire Electrical Discharge Machining

2015 ◽  
Vol 760 ◽  
pp. 551-556 ◽  
Author(s):  
Oana Dodun ◽  
Laurenţiu Slătineanu ◽  
Margareta Coteaţă ◽  
Vasile Merticaru ◽  
Gheorghe Nagîţ
Keyword(s):  
Surface Roughness ◽  
Empirical Model ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Roughness Parameter ◽  
Wire Electrical Discharge Machining ◽  
Power Type ◽  
Surface Roughness Parameter ◽  
Pulse On Time ◽  
Pulse Off Time

Wire electrical discharge machining is a machining method by which parts having various contours could be detached from plate workpieces. The method uses the electrical discharges developed between the workpiece and the wire tool electrode found in an axial motion, when in the work zone a dielectric fluid is recirculated. In order to highlight the influence exerted by some input process factors on the surface roughness parameter Ra in case of a workpiece made of an alloyed steel, a factorial experiment with six independent variables at two variation levels was designed and materialized. As input factors, one used the workpiece thickness, pulse on time, pulse off-time, wire axial tensile force, current intensity average amplitude defined by setting button position and travelling wire electrode speed. By mathematical processing of the experimental results, empirical models were established. Om the base of a power type empirical model, graphical representations aiming to highlight the influence of some input factors on the surface roughness parameter Ra were achieved. The power type empirical model facilitated establishing of order of factors able to exert influence on the surface roughness parameter Ra at wire electrical discharge machining.

Boundary Layers on a Rotating Rough Disk

1994 ◽  
Author(s):  
Ali Heydari ◽  
Ramin Miryan ◽  
Saeid Sharifi
Keyword(s):  
Boundary Layer ◽  
Surface Roughness ◽  
Parabolic Equations ◽  
Roughness Parameter ◽  
Rotating Disk ◽  
Turbulent Fluid Flow ◽  
Uniform Wall Temperature ◽  
Curve Fit ◽  
Uniform Wall ◽  
Finite Difference Solution

Abstract In this paper the turbulent fluid flow over a rotating disk with roughness is considered. The disk is assumed to be at uniform wall temperature. The surface roughness is assumed to influence the turbulent boundary layer by adding a roughness parameter height k. Boundary-layer approximation reduces the elliptic Navier-Stockes equations to parabolic equations, where the Keller-Cebeci method of finite-difference solution is used to solve the resulting system of partial-differential equations. The resulting curve-fit equations to the numerically calculated results for three regions of laminar, transition and turbulent flow is shown to be consistent to those obtained for flow over a flat plate or inside a circular cylinder. Calculations for various surface roughness parameters are made and results are presented.

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