A Novel Shear Plate for Direct Measurements of Bottom Shear Stress Induced by a Model Ship Propeller

Tests have been performed on a vertical pile subject to current only and to a combination of current with normal waves and current with breaking waves. The scour around the pile produced by current only is decreased by normal short waves superimposed upon that current and increased when breaking waves are superimposed upon the current. After analysis of the velocity profiles in the undisturbed area upstream of the pile and next to the pile, the following explanation is found for this phenomenon. When normal short waves are superimposed upon a current, the bottom shear stress of the combination of current with waves is increased more in the undisturbed area than next to the pile in the scour area. This results in a decrease of the scour around the pile. Due to the large values of the orbital velocity under breaking waves this effect is reversed for the combination of a current with breaking and relatively long waves. This results in an increase of the scour around the pile.

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The Wall Shear Stress Signature of a Turbulent Spot: Direct Measurements and Momentum Integral Calculations

Laminar-Turbulent Transition ◽

10.1007/978-3-642-82462-3_75 ◽

1985 ◽

pp. 607-616

Author(s):

C. W. Van Atta ◽

T. S. Mautner

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Turbulent Spot ◽

Direct Measurements ◽

Wall Shear ◽

Momentum Integral

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A COMPARISON OF BOTTOM SHEAR-STRESS APPROACHES USING TWO- AND THREE-DIMENSIONAL FINITE ELEMENT SIMULATION TECHNIQUES

Hydroinformatics ◽

10.1142/9789812702838_0050 ◽

2004 ◽

pp. 407-414

Author(s):

PAUL KAMRATH ◽

JÜRGEN KÖNGETER

Keyword(s):

Finite Element ◽

Shear Stress ◽

Finite Element Simulation ◽

Three Dimensional ◽

Bottom Shear Stress ◽

Simulation Techniques ◽

Element Simulation ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element

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Research on wind-induced nutrient release in Yangshapao Reservoir, China

Water Science & Technology Water Supply ◽

10.2166/ws.2019.180 ◽

2019 ◽

Vol 20 (2) ◽

pp. 469-477

Author(s):

Yu Bai ◽

Jinhua Gao ◽

Ying Zhang

Keyword(s):

Water Quality ◽

Shear Stress ◽

Wind Speed ◽

Nutrient Release ◽

Urban Water ◽

Bottom Shear Stress ◽

Dissolved Phosphorus ◽

Urban Water Use ◽

Lakes And Reservoirs

Abstract Nutrient (total nitrogen (TN) and total phosphorus (TP)) are considered the major indicators to be impacted by wind speed in shallow lakes and reservoirs. As a reservoir situated in Jilin Province, China, Yangshapao Reservoir has been employed for irrigation and urban water use. After 2 years’ observation carried out on water quality and wind speed, it was found that the TN, NH4 and TP are significantly correlated with the bottom shear stress attributed to wind, whereas the dissolved phosphorus (DP) is not. Bottom shear stress is also noticeably associated with dissolved oxygen (DO), thus promoting nutrient release into the water body. In winter, ice can effectively inhibit the wind-induced shear stress, and the TP concentration is evidently lower than in the other seasons. This scenario should be considered in the management of the water quality of the lake and similar lakes.

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