1. System Calculation Muhajir Ab. Rahim School of Mechatronic Engineering

2. Energy Energy is required for every operating systems Neither create nor destroy The operation of any working system, requires that energy be released or converted into a specific form.

3. Energy released Energy stored in coal, oil or wood is released in term of heat by burning. Energy stored in battery is released in the form of electricity when made part of a circuit Energy stored in a compressed spring, when released, is mechanical energy capable of exerting force and moving objects.

4. So what is energy? Energy is defined as the ability to do work. What is hydraulic systems energy? Are mechanical because they exert force and cause movement. Electric motor is the energy source Energy lost is usually converted into heat

5. How do we measure energy? by the amount of work it can accomplish How do we measure mechanical, electrical, heat (thermal) energy? Electrical = Watts Mechanical = horsepower Thermal (heat) = British Thermal Units (BTUs) per hour

6. Horsepower One horsepower is the amount of energy required to lift 550 lbs. 1 foot in 1 second. HP = (F)(d)/550t 1 hp = 746 watts = 2545 BTU/hr Mechanical energy Electrical energy Thermal/ Heat energy

7. HP = W/746 HP = E/2545 What is 1 Watts? What is 1 BTUs? 1 watts is the amount of energy released when 1 volt is applied to a resistance of 1 ohm, producing a current of 1 ampere (W = VA) 1 BTU is the amount of heat required to increase the temperature of 1 lbs of water by 1 0 F

8. Efficiency Efficiency = (Output/Input) x 100 When two or more devices or system components such as an electric motor and hydraulic pump operate in series, the overall efficiency of the combination is found by multiplying the efficiencies of all components.

9. Cylinder Horsepower The amount of energy needed for a cylinder to function as intended Stroke is the length of piston rod travel (normally in inches) HP cyl = (F)(S)/6600t HP cyl = cylinder horsepower F= force required S = Stroke length, in inches t= time, in seconds

10. Fluid Horsepower When a piston rod extends, the force exerted depends upon fluid pressure and the piston area F = PA HP cyl = [(F)(S)]/6600t HP cyl = [(P)(A)(S)]/6600t When a piston moves within a cylinder, the volume of oil moved depends upon the area of the piston face and the length of the stroke. V =AS HP cyl = [(P)(V)]/6600t HP cyl = [(P)/6600].[V/t] Cubic inches per second

11. Using Q to represent gallons per minute Q = [60/231].[V/t] V/t = Q/0.2597 Where HP = [(P)/6600].[V/t] = [(P)/6600].[Q/0.2597] Thus fluid horsepower, HP f = PQ/1714 HP f = fluid horsepower P = pressure in psi Q = flow rate in GPM