# Continuity Equation for Area

on . Posted in Fluid Dynamics

Continuity equation is the moving of a quantity through a pipe in a steady flow.  This formula calculates the initial cross-section area of the pipe.

### Continuity Equation for Area formula

This formula calculates the initial cross-section area of the pipe.

$$A_1 = \rho_2 \; A_2 \; v_2 \;/\; v_1 \; \rho_1$$     (Continuity Equation for Area Formula)

$$\rho_2 = A_1 \; v_1 \; \rho_1 \;/\; A_2 \; v_2$$

$$A_2 = A_1 \; v_1 \; \rho_1 \;/\; \rho_2 \; v_2$$

$$v_2 = A_1 \; v_1 \; \rho_1 \;/\; \rho_2 \; A_2$$

$$v_1 = \rho_2 \; A_2 \; v_2 \;/\; A_1 \; \rho_1$$

$$\rho_1 = \rho_2 \; A_2 \; v_2 \;/\; A_1 \; v_1$$

Symbol English Metric
$$A_1$$ = initial area cross-section $$in^2$$ $$mm^2$$
$$\rho_2$$  (Greek symbol rho) =  final cross-section density $$lbm / ft^3$$ $$kg / m^3$$
$$A_2$$ = final area cross-section $$in^2$$ $$mm^2$$
$$v_2$$ = final cross-section velocity $$ft / sec$$ $$m / s$$
$$v_1$$ = initial cross-section velocity $$ft / sec$$ $$m / s$$
$$\rho_1$$  (Greek symbol rho) =  initial cross-section density $$lbm / ft^3$$ $$kg / m^3$$

Tags: Flow Area