JNTU B.Tech IV Year FLUID POWER SYSTEMS Previous Question Paper (February/March - 2022 - R18)

Pascal's Law states that the pressure exerted anywhere in a confined, incompressible fluid is transmitted equally in all directions throughout the fluid, such that the pressure acts with equal force on equal areas and at right angles to the containing surfaces.

Applications in fluid power include hydraulic jacks, braking systems, and hydraulic presses, where a small input force applied to a small piston generates a significantly larger output force at a larger piston.

Energy losses in hydraulic systems must be considered to ensure efficiency and prevent overheating:

• Viscous friction losses: Occur due to the fluid's internal resistance to flow (viscosity) as it moves through pipes, valves, and fittings.
• Minor losses: Result from flow disturbances caused by changes in pipe diameter, bends, elbows, tees, and valves.
• Leakage losses: Volumetric losses occurring through clearances between moving parts (e.g., in pumps and motors), which reduce overall efficiency.

Hydraulic systems rely on several key components to convert, control, and transmit power:

• Hydraulic Pump: Converts mechanical energy into hydraulic energy. Symbol: A circle with a triangle pointing outward indicating flow direction.
• Hydraulic Actuator (Cylinder/Motor): Converts hydraulic energy back into mechanical energy. Cylinder symbol: A rectangle representing the barrel with a line for the piston rod. Motor symbol: A circle with a triangle pointing inward.
• Control Valves: Regulate pressure, flow rate, and direction. Directional Control Valve (DCV) symbols consist of squares representing valve positions, with arrows indicating flow paths.
• Reservoir: Stores the hydraulic fluid and helps in heat dissipation and contaminant settling. Symbol: A tank represented by a rectangle open at the top.
• Filters: Remove contaminants from the fluid. Symbol: A diamond shape with a dashed line inside.
• Accumulator: Stores hydraulic energy under pressure. Symbol: A circle containing a bladder or piston symbol.