Enter any three of the flow rate, baffle width, baffle height, and design velocity into the calculator to determine the missing variable.

Baffle Size Calculator

Area & Velocity (Main)
Heat Exchanger Cut
Aquarium Sump

Enter any 3 values to calculate the missing variable

Related Calculators

Baffle Opening Area & Flow Formula

The following formulas relate baffle opening size (cross-sectional area) to flow rate using a chosen (or specified) design velocity.

\begin{aligned}
A &= W \cdot H\\
Q &= A \cdot v = W \cdot H \cdot v
\end{aligned}

Variables:

  • Q is the volumetric flow rate (m³/s)
  • A is the opening cross-sectional area (m²)
  • W is the baffle opening width (m)
  • H is the baffle opening height (m)
  • v is the average/design velocity through the opening (m/s)

To calculate the opening area, multiply the baffle width by the baffle height (A = W · H). To estimate flow rate through that opening at a given design velocity, use Q = A · v. To solve for W, H, or v, rearrange Q = W · H · v.

What is a Baffle?

A baffle is a flow-directing or obstructing panel used in various engineering applications, such as tanks, reactors, ducts, and heat exchangers. Baffles are used to control flow patterns to promote mixing, heat transfer, or separation. Depending on the application, they can reduce unwanted swirling/vortexing (for example, in tanks) or increase turbulence (for example, in shell-and-tube heat exchangers) to improve performance.

How to Calculate Baffle Size?

The following steps outline how to calculate the Baffle Size.

  1. First, determine the flow rate (Q).
  2. Next, determine the design/average velocity through the opening (v).
  3. Next, determine the baffle opening width (W).
  4. Next, determine the baffle opening height (H).
  5. Finally, calculate the missing variable using Q = W · H · v (and A = W · H for the opening area).
  6. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge. Check: Q = W · H · v = 2 · 5 · 1 = 10 m³/s.

Flow Rate (Q) = 10 m³/s

Baffle Width (W) = 2 m

Baffle Height (H) = 5 m
Design Velocity (v) = 1 m/s