Drag Constant
Drag Constant - Related Videos
11:30
Buoyancy and Drag on Immersed Bodies
0 Views •
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...
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...
09:14
Paw-Dragging: a Novel, Sensitive Analysis of the Mouse Cylinder Test
0 Views •
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.
08:57
Cross Cylindrical Flow: Measuring Pressure Distribution and Estimating Drag Coefficients
0 Views •
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.
01:18
Drag Force and Terminal Speed
0 Views •
2023
An interesting force in everyday life is the force of drag on an object when it is moving in a fluid. Like friction, the drag force always opposes the motion of an object. Unlike simple friction, the drag force is proportional to some function of the velocity of the object in that fluid. This functionality is complicated and depends upon the shape of the object, its size, its velocity, and the fluid it is in. For most large objects, such as cyclists, cars, and baseballs, that are not moving too...
FAQs
In the linear model, the term −cv supplies a velocity-dependent force in the motion equation. Because c multiplies velocity, changing its value changes how strongly resistance responds to motion. The minus sign makes the force oppose the direction of travel. Including this term in a differential equation allows mathematical analysis of changing velocity rather than treating resistance as a fixed force.
A linear model makes resistive force proportional to speed, whereas a quadratic model makes it depend on speed squared. The latter gives a much stronger increase in resistance as speed grows, so it can represent situations where the linear approximation is no longer suitable. Choosing between these forms changes the differential equation and therefore the predicted motion.
Fluid viscosity, object size, and object shape are identified as factors reflected by the drag constant. Consequently, the same mathematical motion model can produce different behavior when the surrounding fluid or object changes. Treating c as an appropriate parameter for the specific system is important when predicting velocity, resistance, or energy loss.
A model begins by selecting the resistance relationship, such as F = −cv for linear drag or a quadratic dependence for higher-speed conditions. The chosen expression is then incorporated into the equation of motion as a resisting term. Solving or analyzing that differential equation provides predictions for variables such as velocity and terminal behavior.
The drag constant influences how rapidly resistance grows with velocity in a linear-drag model, so it affects the motion toward terminal velocity, the state associated with the model’s limiting speed. Resistance also removes mechanical energy from the moving system. As a result, the parameter helps quantify both speed limits and energy loss in modeled motion.
These models support mathematical descriptions of falling objects, projectile motion, vehicle motion, and fluid transport. In each case, the resistance term connects physical conditions with a differential equation that predicts system behavior. The resulting analysis can compare motion under different parameter values and estimate outcomes such as velocity, terminal behavior, and energy loss.