Cubic inches per minute (in³/min) to Cubic Millimeters per second (mm³/s) conversion

What is cubic inches per minute?

What is Cubic Inches per Minute?

Cubic inches per minute (in$^3$/min or CFM) is a unit of measure for volume flow rate. It represents the volume of a substance (typically a gas or liquid) that flows through a given area per minute, with the volume measured in cubic inches. It's a common unit in engineering and manufacturing, especially in the United States.

Understanding Cubic Inches and Volume Flow Rate

Cubic Inches

A cubic inch is a unit of volume equal to the volume of a cube with sides one inch long. It's part of the imperial system of measurement.

Volume Flow Rate

Volume flow rate, generally denoted as $Q$, is the volume of fluid which passes per unit time. The SI unit for volume flow rate is cubic meters per second ($m^3/s$).

Formation of Cubic Inches per Minute

Cubic inches per minute is formed by combining a unit of volume (cubic inches) with a unit of time (minutes). This describes how many cubic inches of a substance pass a specific point or through a specific area in one minute.

$$Q = \frac{V}{t}$$

Where:

• $Q$ = Volume flow rate (in$^3$/min)
• $V$ = Volume (in$^3$)
• $t$ = Time (min)

Applications and Examples

Cubic inches per minute is used across various industries. Here are some real-world examples:

• Automotive: Measuring the air intake of an engine or the flow rate of fuel injectors. For instance, a fuel injector might have a flow rate of 100 in$^3$/min.
• HVAC (Heating, Ventilation, and Air Conditioning): Specifying the airflow capacity of fans and blowers. A small bathroom fan might move air at a rate of 50 in$^3$/min.
• Pneumatics: Determining the flow rate of compressed air in pneumatic systems. An air compressor might deliver 500 in$^3$/min of air.
• Manufacturing: Measuring the flow of liquids in industrial processes, such as coolant flow in machining operations. A coolant pump might have a flow rate of 200 in$^3$/min.
• 3D Printing: When using liquid resins.

Conversions and Related Units

It's important to understand how cubic inches per minute relates to other units of flow rate:

• Cubic Feet per Minute (CFM): 1 CFM = 1728 in$^3$/min
• Liters per Minute (LPM): 1 in$^3$/min ≈ 0.01639 LPM
• Gallons per Minute (GPM): 1 GPM ≈ 231 in$^3$/min

Interesting Facts

While there's no specific law directly associated with cubic inches per minute itself, the underlying principles of fluid dynamics that govern volume flow rate are described by fundamental laws such as the Navier-Stokes equations. These equations, developed in the 19th century, describe the motion of viscous fluids and are essential for understanding fluid flow in a wide range of applications. For more information you can read about it in the following Navier-Stokes Equations page from NASA.

What is Cubic Millimeters per Second?

Cubic millimeters per second ($mm^3/s$) is a unit of volumetric flow rate, indicating the volume of a substance passing through a specific area each second. It's a measure of how much volume flows within a given time frame. This unit is particularly useful when dealing with very small flow rates.

Formation of Cubic Millimeters per Second

The unit $mm^3/s$ is derived from the base units of volume (cubic millimeters) and time (seconds).

• Cubic Millimeter ($mm^3$): A cubic millimeter is a unit of volume, representing a cube with sides that are each one millimeter in length.

• Second (s): The second is the base unit of time in the International System of Units (SI).

Combining these, $mm^3/s$ expresses the volume in cubic millimeters that flows or passes through a point in one second.

Flow Rate Formula

The flow rate ($Q$) can be defined mathematically as:

$$Q = \frac{V}{t}$$

Where:

• $Q$ is the flow rate ($mm^3/s$).
• $V$ is the volume ($mm^3$).
• $t$ is the time (s).

This formula indicates that the flow rate is the volume of fluid passing through a cross-sectional area per unit time.

Applications and Examples

While $mm^3/s$ might seem like a very small unit, it's applicable in several fields:

• Medical Devices: Infusion pumps deliver medication at precisely controlled, often very slow, flow rates. For example, a pump might deliver insulin at a rate of 5 $mm^3/s$.

• Microfluidics: In microfluidic devices, used for lab-on-a-chip applications, reagents flow at very low rates. Reactions can be studied using flow rates of 1 $mm^3/s$.

• 3D Printing: Some high resolution 3D printers using resin operate by very slowly dispensing material. The printer can be said to be pushing out material at 2 $mm^3/s$.

Relevance to Fluid Dynamics

Cubic millimeters per second relates directly to fluid dynamics, particularly in scenarios involving low Reynolds numbers, where flow is laminar and highly controlled. This is essential in applications requiring precision and minimal turbulence. You can learn more about fluid dynamics at Khan Academy's Fluid Mechanics Section.