Flow rate

Definition

Flow rate is the volume of fluid passing through a given surface per unit time. It is typically measured in units such as liters per second (L/s) or cubic meters per second (m³/s).

5 Must Know Facts For Your Next Test

1. The formula for flow rate is $Q = A \cdot v$, where $Q$ is the flow rate, $A$ is the cross-sectional area, and $v$ is the fluid velocity.
2. Flow rate remains constant in a closed system assuming incompressible flow, according to the principle of continuity.
3. In medical applications, flow rate can be crucial for administering fluids intravenously or measuring blood flow.
4. Bernoulli's equation relates pressure and velocity in fluid dynamics and can be used to derive relationships involving flow rate.
5. The SI unit of flow rate is cubic meters per second ($\text{m}^3/\text{s}$), but other common units include liters per minute (L/min) and gallons per minute (GPM).

Review Questions

• What is the relationship between cross-sectional area, fluid velocity, and flow rate?
• How does Bernoulli’s equation relate to the concept of flow rate?
• Why is it important to consider flow rate in medical applications?

Related terms

Velocity:

Velocity refers to the speed of something in a given direction. In fluid dynamics, it indicates how fast the fluid particles are moving.

Bernoulli's Equation:

$P + \frac{1}{2}\rho v^2 + \rho gh = \text{constant}$; this principle describes the conservation of energy in flowing fluids.

Continuity Equation:

$A_1 v_1 = A_2 v_2$; this equation states that for an incompressible fluid, the product of cross-sectional area and velocity remains constant along a streamline.