# Fluid power fundamentals and calculations

## Fluid power fundamentals and calculations

**Fluid Power Fundamentals**

**Fluid power**is the use of fluids under pressure to generate, control, and transmit power.- Fluid power systems include
**hydraulic**(liquid) and**pneumatic**(gas, usually air) systems. - In a fluid power system, the fluid in a
**closed system**is pressurised and transmitted through tubes or hoses to create motion. **Pascal’s law**states that a pressure change occurring anywhere in a confined incompressible fluid is transmitted throughout the fluid such that the same change occurs everywhere.- Key components of fluid power systems typically include a
**reservoir**, a**pump**(or compressor for pneumatics),**valves**for direction, speed and pressure control, and**actuators**(like cylinders or motors that convert fluid power into mechanical power).

**Fluid Properties**

**Density**,**viscosity**, and**bulk modulus**are key properties impacting the behavior of fluids.- Density (ρ) is the mass of a substance per unit volume, typically measured in kilograms per cubic meter (kg/m^3).
**Viscosity (μ)**is a measure of a fluid’s resistance to shear stress or flow. It’s measured in pascal-seconds (Pa.s).- The
**bulk modulus (K)**of a substance measures the substance’s resistance to uniform compression. It is given in units of pressure, usually gigapascals (GPa).

**Fluid Power Calculations**

- The basic equation for
**pressure**is: P = F/A, where P is pressure, F is force, and A is the area over which the force is distributed. - The flow rate Q of a pump is calculated using
**Q = V/t**, where V is the volume and t is the time it takes for the volume to change. - The
**work**done by a hydraulic/pneumatic cylinder can be calculated using W = F * d, where F is the force and d is the distance moved. - The power of a fluid power system can be calculated using
**P = W/t**, where P is power, W is the work done, and t is the time it takes to do the work. - To calculate the fluid force acting on a surface, you can use
**F=PA**, where F is the force, P is the pressure, and A is area.

**Fluid Power Applications**

- Fluid power systems are used in a variety of engineering applications including vehicle systems (brakes, steering, lifts), industrial machines (presses, conveyors, lifts), and mobile equipment (construction, farming, marine).
- They are also used in the control systems for automated machines and in safety and emergency systems.

**Health and Safety**

- It’s important to remember that fluid power systems can be dangerous if not correctly installed, maintained and used.
- Always follow the manufacturer’s instructions, workplace safety guidelines and use personal protective equipment where necessary.