Fluid Mechanics Flashcards
What is “fluid mechanics”?
The study of the forces acting on an object through the air or water.
What is the Difference between Air Resistance and Drag?
AIR RESISTANCE= an opposing force in the air
DRAG= an opposing force in the water
What is bad about AR and Drag and what has been done to combat this?
Air resistance and Drag have a negative impact on speed/ velocity.
A lot of money has been invested to reduce AR and DRAG
You don’t want to waste energy expenditure overcoming these during performance
Wind tunnels and fluid dynamic programmes analyse the effects of each
Aim to create the best clothing, equipment and techniques
What factors does AR depend on?
VELOCITY- The greater the velocity the greater the air resistance, velocity cannot be reduced to minimise AR so there must be other factors considered.
FRONTAL CROSS SECTIONAL AREA- of the moving body- larger= increase AR
A ski jumper will actively increase their FCSA
STREAMLINING AND SHAPE- the more streamlined, the lower AR/ drag will be
MASS- if an object is relatively heavy = AR has less of an affect - increased mass= increased momentum
SURFACE CHARACTERISTICS- the smoother the surface, the lower the AR and DRAG.
Describe how a downhill skier applies the factors affecting AR ?
Large mass (90kg) allows them to generate a huge amount of momentum
Adapt low crouched position/ straight= minimise fcsa
Wear Tear drop shaped helmet= streamlined
Wear tight fitting lycra= smooth surface
Describe how a cyclist applies the factors affecting AR?
Lightweight carbon fibre bicycle design with aerodynamic features (disk wheels) which reduce energy expenditure and minimise AR
Aerodynamic riding position- shoulders forewords, high seat position to tilt body forewords, narrow handlebars= small fcsa
Aerodynamic helmets- glossy surface- specialised shape to streamline airflow
Tight fitting lycra skin suits and smooth socks pulled over the shoes= seamlessly mould to lower legs. 7
Shaved legs, face and hands to maximise smoothness
What factors affect DRAG (IN THE WATER)
VELOICTY- the faster an object is travelling through the water, the greater the drag acting upon the object
FRSA- The smaller the frontal cross sectional area of an object in the water, the less effect drag has on it
STREAMLINING AND SHAPE- A streamlined shape can travel through the water more easily and SMOOTHNESS of suits = less negatively impacts drag
Mass- if an object is relatively heavy, drag (in the water) will have less of an effect than it would on a lighter object- INCREASED MOMENTUM.
What’s the relationship with mass and AR and DRAG?
As Mass increases, momentum increases
This decreases AR and DRAG
What’s the acronym for factors affecting fluid mechanics?
Vets For Sad Smooth Meerkats
