8.7.- FLUID MACHINES

Based on this definition, fluid machines can be classified as follows:

• Power generating machines.

• Turbines: torque and power are provided in the shaft as a result of the variation of the amount of motion of the fluid that passes through them.
• Wind turbines: the kinetic energy of the wind is transformed into mechanical energy.

• Power consuming machine.

• Pumps: mechanical energy is supplied to the fluid in the form of work to replace the pressure drop suffered by fluids due to friction in the pipes.
• Fans: large quantities of gas are moved as a result of the pressure increase generated. There are two basic types of fans: the blower or centrifugal fan and the axial flow fan.
• Compressors: a lower amount of flow is moved if compared to the fans, but the pressure increase is much higher.

Machines have been designed since ancient times with the purpose of using the energy provided by nature. For example, the conversion of mechanical energy into hydraulic energy by machines is of great interest to most engineers and technicians. Some classical hydraulic machines are the Roman water wheel or the hydraulic press. At present, we are surrounded by fluid machines in our everyday lives. Some examples are the aircraft engines, the circuit pumps in swimming pools or cars, the windmills, the cooling fans in computers or the fans used at home.