Friction Drag
Friction Drag - Related Videos
11:30
Buoyancy and Drag on Immersed Bodies
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2023
Source: Alexander S Rattner and Sanjay Adhikari; Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA Objects, vehicles, and organisms immersed in fluid mediums experience forces from the surrounding fluid in the form of buoyancy- a vertical upward force due to fluid weight, drag- a resistive force opposite the direction of motion, and lift- a force perpendicular to the direction of motion. Prediction and characterization of these forces is...
08:25
Friction
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2023
Source: Nicholas Timmons, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA The goal of this experiment is to examine the physical nature of the two types of friction (i.e., static and kinetic). The procedure will include measuring the coefficients of friction for objects sliding horizontally as well as down an inclined plane. Friction is not completely understood, but it is experimentally determined to be proportional...
01:23
Drag
0 Views •
2025
Drag is a resistive force opposing an object’s motion through a fluid, resulting from surface pressure and shear forces. It comprises two components: a perpendicular one from pressure and a tangential one from shear stress. Accurate drag calculations use pressure and wall shear stress distributions, often determined through Computational Fluid Dynamics (CFD) or wind tunnel testing. The drag coefficient, a dimensionless measure, depends on factors like shape, Reynolds number, Mach number, Froude...
08:57
Cross Cylindrical Flow: Measuring Pressure Distribution and Estimating Drag Coefficients
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2023
Source: David Guo, College of Engineering, Technology, and Aeronautics (CETA), Southern New Hampshire University (SNHU), Manchester, New Hampshire The pressure distributions and drag estimations for cross cylindrical flow have been investigated for centuries. By ideal inviscid potential flow theory, the pressure distribution around a cylinder is vertically symmetric. The pressure distribution upstream and downstream of the cylinder is also symmetric, which results in a zero-net drag force.
09:14
Paw-Dragging: a Novel, Sensitive Analysis of the Mouse Cylinder Test
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Cited by 53 •
2015
Classical forelimb asymmetry analysis of the cylinder test is routinely used to assess behavioural deficits in rats following brain injury or stroke; however, it fails to detect consistent deficits in mice. This study demonstrates that quantifying paw-dragging behaviour is a more sensitive analysis of brain injury in mice.
FAQs
The no-slip condition makes the fluid velocity at the wall zero. Moving away from the solid surface, velocity rises through the boundary layer toward the free-stream value. This velocity change across the layer is associated with viscous shear and determines how the moving fluid interacts with the surface locally.
Fluid viscosity and flow speed alter the resistance, while surface area determines how much solid boundary contacts the moving fluid. Surface roughness also changes the drag response. Considering these variables together helps engineers compare designs and anticipate how operating conditions or surface condition may increase energy loss.
The kinetic energy lost from the flow does not simply disappear; it is converted into heat through viscous shear. This conversion makes friction drag an energy-loss issue rather than only a force on a surface. In engineering analysis, tracking that loss helps predict efficiency for moving-fluid systems and evaluate design changes.
An evaluation begins by specifying the fluid viscosity, flow speed, surface area, and roughness relevant to the component. Engineers then assess boundary-layer behavior and the resulting resistance, followed by prediction of associated energy loss. Comparing these results across candidate designs or surface conditions supports choices intended to improve efficiency.
Applications span aircraft, vehicles, ships, pipelines, and turbines. In each case, fluid movement along solid surfaces can impose resistance and consume part of the flow’s available kinetic energy as heat. Studying this effect helps engineers predict energy loss and compare approaches for improving aerodynamic or hydrodynamic efficiency.
Surface treatments and design changes provide engineering options because surface roughness and boundary-layer behavior influence friction drag. A useful comparison keeps the relevant fluid and operating conditions in view, then examines whether an altered surface or design changes predicted resistance and energy loss. This supports efficiency improvements in aerodynamic and hydrodynamic systems.