Page 1 - Contents
Page 2 - Introduction
Page 2 - Activity 1: Cessna-310 Performance Data
Page 3-4 - Activity 2: Propeller Parameter Definitions
Page 4 - Activity 3: Results of Engine RPM vs Fuel Flow
Page 5-6- Activity 4: Axial Momentum Theory
Page 7-8 - Activity 5: Propeller Efficiency & Power Coefficient
Page 8-9- Activity 6: Fuel Flow
Page 9 - Activity 7: Conclusion
Page 10- Reference
The function of a propeller on an aircraft is to provide propulsive force. This lab report was aimed at studying and analysing the propeller and some engine properties of a Cessna 310R. The axial momentum theory, advance ratio and the energy method for fuel flow estimation are used in this analysis.
CESSNA 310 PERFORMANCE DATA
MTOW: 5, 500 pounds (2576 kg)
Fuel weight: 102.00 gal or (618 L)
Wing span: 35 ft 0 in (10.67 m)
Engine type: Two 213kW (285hp) Continental IO-520-MB fuel injected piston engines. Propeller diameter: 74-76 in
No. of blades/prop: 3
Wing area: 16.3m2 (175sq ft).
Engine max continuous power: 39 in.hg. and 2500 RPM
Take-off power: 285 hp (213 kW)
Fuel flow: 120 lts/hr
Take-off speed: 92 kts or 47.328m/s
Cruise speed: 267km/h (144kts)
Cruise altitude: 19,750ft.
Range: 1170km (632nm) - 1617km (873nm)
Definition of propeller parameters
Forward speed: The rate of movement/ advancement of the propeller relative to the air. Rpm: This is the rotational speed of the propeller, it is measured in revolutions per min. Mtip : Mach Number tip, this is the quality of the propeller tip to reach the mach number as a result of increase in RPM. No. of blade: A propeller has a number of blades, in a Cessna 310, the number of blades is 3. Diameter (d): the distance across the circle swept by the extreme tips of the propeller blades. In the majority of cases, the larger the diameter the greater the propeller efficiency. Pitch ((): The pitch is a measure of the orientation of the propeller on a plane normal to the axis of rotation. reference line for the calculation of the pitch is the chord. Type of blade section: cross section of a propeller blade in a plane parallel to that containing the axis of rotation. Chord distribution along radius: This is the various distribution of the length of the chord from the leading edge to the trailing edge as a result of geometrical shape of the blasé section. Chord length at the hub is greater than at the tip. Tip geometry: This is the extreme part of a propeller at the tip which is geometrically thinner than the rest of the propeller blade. Hub geometry: This is the root of the propeller which is quiet bigger than the rest of the propeller blade.
Propeller stream tube: This is the axial direction and change in flow momentum along a stream-tube starting upstream, passing through the propeller, and through the downstream. [pic]
Propeller disk: This is total area on which the propeller rotates.. Propeller is considered as a rotating disk instead of consisting the blades which are rotating in the air. The rotating disk imparts axial momentum to the air passing through it.
Measuring engine rpm vs fuel flow from cockpit instrumentation. The table below shows the measured values of the fuel flow at 1000 rpm, 1500 rpm and 2000 rpm.
|RPM |FUEL FLOW (kg/s) | |1100 |0.003527916kg/s | |1500 |0.004787886kg/s | |2000 |0.007811814kg/s |
Axial Momentum Theory
This is a theoretical mechanism in which the rotating power of a propeller is converted into useful thrust. In this theory, the propeller is considered as a rotating disk instead of consisting the blades which are rotating in the air....