Well – sorta:

While it seems complex, the carburetor consists of a “barrel” (or a series of “barrels) that provide a means of ambient air to pass through a venturi in route to the intake manifold. The venturi narrows in section and then opens again, causing the airflow to increase in speed in its narrowest part. The throttle butterfly rotates in a manner that ranges from nearly no restriction (WOT) to nearly closed (idle) controlling the flow of air through the carburetor throat and thus the quantity of air/fuel mixture delivered, which regulates engine speed.

Fuel is introduced into the air stream through small holes at the narrowest part of the venturi. Fuel flow is in response to a particular pressure drop in the venturi and is adjusted by means of calibrated openings in the fuel path typically called jets.

When the throttle butterfly begins to open (from the fully closed position), it exposes additional fuel delivery holes where there is a low pressure area created by the butterfly blocking air flow; these allow more fuel to flow as well as compensating for the reduced vacuum that occurs when the throttle is opened, enabling the transition to metering fuel flow through the regular open throttle circuit.

As the throttle continues to open, the manifold vacuum drops (since there is less restriction on the airflow), reducing the flow through the idle and off-idle circuits. This is where the venturi shape of the carburetor throat comes into play, due to Bernoulli's principle (i.e., as the velocity increases, pressure falls). The venturi raises the air velocity, creating high speed and thus low pressure, sucking fuel into the air stream through a nozzle or nozzles located in the center of the venturi. Sometime carburetors use booster venturis (annular discharge) within the primary venturi to increase the effect.

When the throttle is closed, the airflow through the venturi drops to a pressure that cannot maintain this fuel flow, and the idle circuit takes over.

Bernoulli's principle, which is a function of fluid velocity, has a dominant effect for large openings and large flow rates. Since fluid flow at small scales and low speeds is dominated by viscosity, Bernoulli's principle is ineffective at idle or slow running. The idle and slow running jets are typically placed after the throttle valve where the pressure is reduced partly by viscous drag, rather than by Bernoulli's principle.

My two cents worth - excerpted from some old archives rattling around my brain. Hope it helps.

Regards All,
Glenn