Why is Mach 1 at throat?

Why is Mach 1 at throat?

When the nozzle isn’t choked, the flow through it is entirely subsonic and, if you lower the back pressure a little, the flow goes faster and the flow rate increases. As you lower the back pressure further the flow speed at the throat eventually reaches the speed of sound (Mach 1).

What is choking in nozzle?

Nozzle choking is a fluid dynamic condition associated with the venturi effect. When a flowing fluid at a given pressure and temperature passes through a constriction (such as the throat of a convergent-divergent nozzle or a valve in a pipe) into a lower pressure environment the fluid velocity increases.

How do you calculate throat velocity?

In order to find the velocity at the throat as V = c(Ma) we have to find c which requires the temperature. This is found from equation 11.56, using the standard temperature from table 1.7, T0 = 59oF = 518.67 R. We can now compute the sound speed using the gas constant for air from Table 1.7: R = 1716 ft·lbf/slug·R.

Why is choked flow bad?

Choked flow is bad because you can’t get any more flow by increasing the pressure drop… with a fixed orifice and constant inlet conditions. This valve has a max Cv of 53.6 so there is plenty of capacity for the valve to open more to get more flow through the valve.

When nozzle is used in blast furnace then it called as?

tuyeres
Explanation: Nozzles used in blast furnaces are called tuyeres.

Can liquid flow be choked?

A: No, liquids can also choke. Choked flow in liquids occurs as the velocity at the vena contracta increases, causing the local pressure to drop below the liquid’s vapor pressure. At this point, the liquid will start to form vapor which takes up additional space, leading to the choked condition.

What is Sonic choking?

Fox critical flow venturies or sonic chokes are used to maintain constant, stable gas flow rates when discharge pressure or conditions can vary. The sonic choke establishes constant flow rate unaffected by ΔP. With no moving parts, chokes are the simplest way to regulate gas flows.