Hey, stuck on this question in my hydraulics course:
Question involves lubricating oil pumped around a large piece of machinery.
Density of oil = 810 km/m3.
Viscosity = 0.01 kg/m.s throughout the system.
Flow rate is 0.140 Litres/sec
Pipe diameter = 3mm
Pressure at point A = 1.55 kPa.
Point A is 5m above the ground.
Point B is 36.5m above the ground. Question requires pressure to be found at this point ignoring minor losses and friction.
The Attempt at a Solution
I attempted to solve this problem using Bernoulli equation: (pA/Pg)+(VA2/2g) + ZA = (pB/Pg)+(VB2/2g)+ZB, However the result I get is negative and looks all wrong.
We were given very limited information but I assume we have enough info to answer the question. I don't see how the pressure at point A could possibly be only 1.55 kPa, given the oil is being lifted 31.5m high and 1.55 kPa is many times less pressure than even a car tyre.
The flow rate also seems unrealistically high, and the pipe diameter seems unrealistically narrow.
The question only specifies "pressure = 1.55 kPa". Is it possible they meant dynamic pressure?