scholarly journals EFFECT OF MONSOONAL TRANSITION OF WIND FLOW PATTERN OF CAUVERY DELTA ZONE- A CASE STUDY

2021 ◽  
Vol 10 (6) ◽  
Keyword(s):  
Flow Pattern ◽  
Wind Flow ◽  
Cauvery Delta

Modelling the wind flow pattern around a parabolic sand dune

1990 ◽  
Vol 32 (1-2) ◽  
pp. 89-94 ◽  
Author(s):  
J.J. Finnigan ◽  
D. Neil ◽  
B.G. Lees ◽  
R.J. Croome ◽  
M. Woodgate
Keyword(s):  
Flow Pattern ◽  
Sand Dune ◽  
Wind Flow

Wind speed modeling over complex terrain with the artificial neural network in the measure-correlate-predict technique: A case study of Malaysia

2021 ◽  
pp. 0309524X2110558
Author(s):  
Yong Kim Hwang ◽  
Mohd Zamri Ibrahim ◽  
Marzuki Ismail ◽  
Ali Najah Ahmed ◽  
Aliashim Albani
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Spatial Modeling ◽  
Complex Terrain ◽  
Simulated Data ◽  
Wind Flow ◽  
Acceptable Accuracy ◽  
Network Measure ◽  
Artificial Neural

This study aimed to create a Malaysian wind map of greater accuracy. Compared to a previous wind map, spatial modeling input was increased. The Genetic Algorithm-optimized Artificial Neural Network Measure–Correlate–Predict method was used to impute missing data, and managed to control over- or under-prediction issues. The established wind map was made more reliable by including surface roughness to simulate wind flow over complex terrain. Validation revealed that the current wind map is 33.833% more accurate than the previous wind map. Furthermore, the correlation coefficient between wind map-simulated data and observed data was high as 0.835. In conclusion, the new and improved wind map for Malaysia simulates data with acceptable accuracy.

Effect of Axial Gap between Diffuser Inlet and Impeller on Efficiency and Flow Pattern of Centrifugal Fans

2013 ◽  
Vol 446-447 ◽  
pp. 621-625
Author(s):  
Mojtaba Gholamian ◽  
Gurram Krishna Mohan Rao ◽  
Bhramara Panitapu
Keyword(s):  
Numerical Simulations ◽  
Flow Pattern ◽  
Squirrel Cage ◽  
Centrifugal Fans ◽  
And Performance

Inlet is one of the basic elements of squirrel cage fan that can have great effect on performance and losses, especially between inlet exit and first section of impeller width. In this paper the effect of axial gap between inlet diffuser and impeller on performance and flow pattern is considered. Three diffuser inlet sizes with respect to impeller size (smaller, nearly same and bigger than inner impeller diameter) and three axial gaps within the available dimensions of the casing and impeller were chosen. Numerical simulations were performed to find the effect of this axial gap on flow pattern, performance and efficiency. From the simulation of each case study, flow pattern and its mechanism and the causes that affecting the efficiency and performance due to axial gap are analyzed and presented.

Flow Pattern and Efficiency Changes of Squirrel Cage Fans due to Inlet Diffuser Diameter Changes - Using CFD Method and Experimental Validation

2013 ◽  
Vol 446-447 ◽  
pp. 626-630
Author(s):  
Mojtaba Gholamian ◽  
Gurram Krishna Mohan Rao ◽  
Panitapu Bhramara
Keyword(s):  
Flow Pattern ◽  
Additional Element ◽  
Performance Point ◽  
Squirrel Cage ◽  
Head Pressure ◽  
Experimental Validations ◽  
Cfd Method ◽  
Present Case Study ◽  
Proper Solutions

Inlet is one the basic elements of squirrel cage fans that has a significant effect on fan performance and efficiency. Recently using the CFD calculation methods with sufficient related tools for finding the flow pattern and related parameters, applying modifications and representing proper solutions, has being increased. In the present case study to study the effect of inlet diffuser diameter on the fan efficiency and flow pattern, using numerical simulations and experimental validations, three different inlet diffuser diameters are used as inlet instead of inlet nozzle. To simulate these cases some geometries with special additional element, proper mesh pattern and size and proper turbulence model was chosen.It is observed performance and efficiency curves of fans with respect to use of inlet nozzle are more flattened with higher magnitude. So fan operation around the best performance point is more stable without significant fluctuation of head pressure and efficiency.

scholarly journals 3D-CFD Study of Oblique Streamlining Membranes on the Roof-Top of a Low-Rise Building, Targeting Pedestrian Comfort-A Case Study

2020 ◽  
pp. 51-68
Author(s):  
Alireza Mani ◽  
Kasra Amini
Keyword(s):  
Separated Flow ◽  
The Body ◽  
Navier Stokes ◽  
Wind Flow ◽  
Street Canyons ◽  
Controlling Mechanism ◽  
3D Geometry ◽  
The Subject ◽  
Reynolds Average

Considering the cubic nature of the most frequent geometries among the urban elements and their configurations, the manipulation of the free stream wind flow around the enormous objects, as well as within relatively narrow corridors, such as street canyons is significant in many regards. One of its instances could be mentioned as pedestrian comfort. In this case study, the implementation of an Oblique Streamlining Membrane (OSM) has been studied on a sub-branch of a low rise, but bulky, building, over which a roof-top outdoor food court area has been primarily designed. The OSM serves as the streamlining mechanism, preventing the roof-top area from the intense fluctuations of the wind flow after the flow is separated from the inlet corner side of the building in question. The optimization of sub-geometries and the proof of the concept for the OSM flow controlling mechanism were the subject of the current manuscript, for which a 3D numerical Reynolds Average Navier-Stokes (RANS) scheme has been used. An unstructured computational grid has been applied around the 3D geometry of the entire building and its sub-branching details, which is in contrast with most studies on full-scale geometries, tending to have simplifications on the body to reach a more generalized set of results. All cases have been numerically tested with and without the presence of the OSM. This comparison has been the grounds for proving the effectivity of the said flow controlling mechanism to eliminate high gradient fluctuations of the separated flow off the roof corners. This has led to pedestrian/resident comfort on the roof-top food court area located on top of the building.

scholarly journals Comparison of Ensemble Kalman Filter–Based Forecasts to Traditional Ensemble and Deterministic Forecasts for a Case Study of Banded Snow

2012 ◽  
Vol 27 (1) ◽  
pp. 85-105 ◽  
Author(s):  
Astrid Suarez ◽  
Heather Dawn Reeves ◽  
Dustan Wheatley ◽  
Michael Coniglio
Keyword(s):  
Kalman Filter ◽  
Flow Pattern ◽  
Ensemble Kalman Filter ◽  
Initial Conditions ◽  
Closed Surface ◽  
Flow Patterns ◽  
Precipitation Forecast ◽  
Ensemble Mean ◽  
Correct Location

Abstract The ensemble Kalman filter (EnKF) technique is compared to other modeling approaches for a case study of banded snow. The forecasts include a 12- and 3-km grid-spaced deterministic forecast (D12 and D3), a 12-km 30-member ensemble (E12), and a 12-km 30-member ensemble with EnKF-based four-dimensional data assimilation (EKF12). In D12 and D3, flow patterns are not ideal for banded snow, but they have similar precipitation accumulations in the correct location. The increased resolution did not improve the quantitative precipitation forecast. The E12 ensemble mean has a flow pattern favorable for banding and precipitation in the approximate correct location, although the magnitudes and probabilities of relevant features are quite low. Six members produced good forecasts of the flow patterns and the precipitation structure. The EKF12 ensemble mean has an ideal flow pattern for banded snow and the mean produces banded precipitation, but relevant features are about 100 km too far north. The EKF12 has a much lower spread than does E12, a consequence of their different initial conditions. Comparison of the initial ensemble means shows that EKF12 has a closed surface low and a region of high low- to midlevel humidity that are not present in E12. These features act in concert to produce a stronger ensemble-mean cyclonic system with heavier precipitation at the time of banding.

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