Effect of shape difference of Micro Surface Roughness on aerodynamic characteristics of rotating golf ball

Wind speed spatial distribution over the territory of Ukraine built based on weather stations measurements has been analyzed. Interpolated field of wind speed averaged over 1981-2010 indicated fairly heterogeneous structure with a number of artificial spots of larger/smaller values compared to surrounding areas. The main reason of such heterogeneity might be associated with representativeness of observation site regarding the landscape zone. It is well known that surrounding obstacles have a great impact on wind flow in horizontal direction. In order to solve this problem we have corrected sub-daily wind speed data measured at 207 meteorological stations of Ukraine for the period of 1981-2010 according to the open terrain conditions and the standard height (10 m). Generally, aerodynamic characteristics (e.g. surface roughness length) of measurement sites are needed in order to perform such adjustment. However, the only usable parameter available at a climatological reference book is horizon closure degree. The research revealed significant relationship between this characteristic and wind speed records (Pearson correlation coefficient equals -0.58). Given that horizon closure degree could not be used in correction procedure directly, surface roughness length has been calculated for 10 stations and statistical relationship has been determined between these two parameters. Based on the obtained relation and additional information we have found roughness length for all 207 stations at eight directions. Supplementary materials for analysis included observation sites description and Google Earth snapshots as well. In the final step, there has been applied a correction formula derived from the neutral logarithmic profile of wind speed in the atmospheric surface layer. The output of the research is new database of corrected wind speed measurements for the multiyear period. These results have been compared with observations. Mean 30-yr corrected speeds are featured by more homogeneous distribution over Ukraine and mostly higher values (with positive mean spatial bias ~0.35 m/s). The applied method allowed us to remove uncertainties related to differences in vertical level of measurements and considerably eliminate influence of the micro-scale terrain inhomogeneity. Obtained datasets may facilitate to perform spatial interpolation and further development of Ukrainian Wind Atlas.

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Aerodynamic characteristics of high speed spinning golf ball : Effect of flow direction change

The Proceedings of Conference of Kyushu Branch ◽

10.1299/jsmekyushu.2003.56.145 ◽

2003 ◽

Vol 2003.56 (0) ◽

pp. 145-146

Author(s):

Taketo MIZOTA ◽

Sungmin PARK ◽

Hiroyuki MIYAHISA ◽

Yasunori NAKAMURA

Keyword(s):

High Speed ◽

Flow Direction ◽

Aerodynamic Characteristics ◽

Golf Ball ◽

Direction Change

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S0504-1-3 Aerodynamic Characteristics and Flow Pattern around a Golf Ball with Rotation

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2010.2.0_85 ◽

2010 ◽

Vol 2010.2 (0) ◽

pp. 85-86

Author(s):

Koji MUTO ◽

Hiroo OKANAGA ◽

Katsumi AOKI

Keyword(s):

Flow Pattern ◽

Aerodynamic Characteristics ◽

Golf Ball

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Effect of Surface Roughness on the Aerodynamic Characteristics of a Symmetrical Airfoil

Wind Engineering ◽

10.1260/0309524043028136 ◽

2004 ◽

Vol 28 (5) ◽

pp. 547-564 ◽

Cited By ~ 13

Author(s):

Walid Chakroun ◽

Issa Al-Mesri ◽

Sami Al-Fahad

Keyword(s):

Surface Roughness ◽

Aerodynamic Characteristics ◽

Effect Of Surface

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Investigation of rapid manufacturing technology with ABS material for wind tunnel models fabrication

Journal of Polymer Engineering ◽

10.1515/polyeng-2012-0089 ◽

2012 ◽

Vol 32 (8-9) ◽

pp. 575-584 ◽

Cited By ~ 7

Author(s):

Saeed Daneshmand ◽

Cyrus Aghanajafi ◽

Hossein Shahverdi

Keyword(s):

Surface Roughness ◽

Wind Tunnel ◽

Raw Materials ◽

Dimensional Accuracy ◽

Aerodynamic Characteristics ◽

Wind Tunnels ◽

Rapid Manufacturing ◽

Material Strength ◽

Wind Tunnel Testing ◽

Tunnel Testing

Abstract Nowadays, several procedures are used for manufacturing wind tunnel models. These methods include machining, casting, molding and rapid prototyping. Raw materials such as metals, ceramics, composites and plastics are used in making these models. Dimension accuracy, surface roughness and material strength are significant parameters which are effective in wind tunnel manufacturing and testing. Wind tunnel testing may need several models. Traditional methods for constructing these models are both costly and time consuming. In this research, a study has been undertaken to determine the suitability of models constructed using rapid manufacturing (RM) methods for use in wind tunnel testing. The aim of this research is to improve the surface roughness, dimensional accuracy and material strength of rapid manufacturing models for testing in wind tunnels. Consequently, the aerodynamic characteristics of three models were investigated and compared. The first model is made of steel, the second model from FDM-M30, and the third model is a hybrid model. Results show that metal models can be replaced by hybrid models in order to measure aerodynamic characteristics, reduce model fabrication time, save fabrication cost and also to verify the accuracy of aerodynamic data obtained in aerospace industry.

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