Q.No. 6.10:- Explain the working of carburetors of a motorcar using Bernoulli’s equation.

Q.No. 6.10:- Explain the working of carburetors of a motorcar using Bernoulli’s equation.

Ans:- The carburetor of a car engine uses a Venturi duct to feed the correct mix of air and petrol to the cylinders. Air is drawn through the duct and along a pipe to the cylinders. A tiny inlet at the side of the duct is fed with petrol. The air through the duct moves very fast, creating low pressure in the duct, which draws petrol vapors into the air stream.

Extra Elucidation

    A venturi is a tube with a convex taper, (one end wider than the other). As air enters the wider end it's squeezed into the narrower section of the tube, lowering the air's pressure. The area of lowest pressure is just past the narrowest point and is called the depression. This has always seemed

counterintuitive to me, but Bernoulli's Principle outlines the fluid dynamics

involved in this effect. This lowered pressure, or comparative vacuum is separate from the engine vacuum. A variable venturi varies the venturi diameter at the depression 
by raising or lowering an obstruction. This obstruction is called a slide. On a CV the slide 
is called a piston or diaphragm valve.