Litres per hour (l/h) to Cubic inches per minute (in³/min) conversion

What is litres per hour?

Litres per hour (L/h) is a common unit for measuring the rate at which a volume of liquid flows. Understanding its meaning and applications can be helpful in various fields.

Understanding Litres per Hour (L/h)

Litres per hour (L/h) is a unit of volume flow rate. It indicates the volume of liquid, measured in litres, that passes a specific point in one hour. In simpler terms, it tells you how many litres of a substance are moving per hour.

Formation of the Unit

The unit is formed by combining two fundamental units:

• Litre (L): A metric unit of volume, defined as the volume of one kilogram of pure water at its maximum density (approximately 4°C).
• Hour (h): A unit of time, equal to 60 minutes or 3600 seconds.

Therefore, 1 L/h means that one litre of a substance flows past a point in one hour.

Formula and Calculation

The flow rate ($Q$) in litres per hour can be calculated using the following formula:

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

Where:

• $Q$ = Flow rate (L/h)
• $V$ = Volume (L)
• $t$ = Time (h)

Real-World Examples

Litres per hour are used in many practical applications.

• Water Usage: A household might use 500 L/h when all taps, showers, and appliances are running at once.
• Medical Infusion: An IV drip might deliver medication at a rate of 0.1 L/h.
• Fuel Consumption: A car might consume 5 L/h of fuel while idling.
• Industrial Processes: A chemical plant might pump reactants at a rate of 2000 L/h into a reactor.
• HVAC System: Condensate from a home air conditioner might drain at a rate of 1 L/h on a humid day.

Interesting Facts and Connections

While there isn't a specific "law" directly associated with litres per hour, the concept of flow rate is central to fluid dynamics, which is governed by laws like the Navier-Stokes equations. These equations describe the motion of viscous fluids and are fundamental in engineering and physics.

Conversion

Often, you might need to convert between L/h and other flow rate units. Here are some common conversions:

• 1 L/h = 0.001 $m^3$/h (cubic meters per hour)
• 1 L/h ≈ 0.264 US gallons per hour

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.