05-07-2012, 11:41 AM
Air consumption measurement
Air consumption measurement.docx (Size: 16.68 KB / Downloads: 37)
Air box method
• Orifice in the induction tube
• Reading will be pulsating & unreliable
• All nozzle,orifice,venturi have a square law between flow rate & differential pressure
• Which leads to severe errors on unsteady flow
• Orifice can be used if pressure pulsations could be damped out by some means
• To fit an air box of suitable volume (500-600 Vs in single cylinder and less in multi cylinder)
• Orifice placed in the side of the box far from engine
• Air box contains air tank, orifice plate, open to engine, temp. & pressure measuring devices
VISCOUS FLOW METER
• smoothing capacity often requires to be inconveniently great and too small a volume will lead to surprisingly large errors if we go for orifice
• the range of flows covered by a single orifice is rather restricted since the rate of flow is proportional to the square root of the head
• Viscous flow meter gives accurate reading for pulsating flows
• Viscous resistance is the principal source of pressure loss
• Linear relationship between pressure difference & flow instead of square law
• Viscous element is honeycomb passage
Fuel consumption measurement
• Automatic burette flow meter
• Orifice flow meter
• Gravimetric flow meter
• Fuel Consumption measurement in vehicles