20-11-2012, 01:03 PM
DATA ACQUISITION OF FLEX NOZZLE USING STRAIN GUAGES AND LVDT’S
DATA ACQUISITION OF FLEX.pptx (Size: 351.11 KB / Downloads: 48)
INTRODUCTION TO SOLID ROCKET MOTOR
MAIN COMPONENTS OF A SOLID ROCKET MOTOR:
The CASE.
Propellant Grain.
Thermal Insulation.
The Ignition System.
The Nozzle.
THE CASE: It is the metal made of high resistance steels and other composite materials like glass, carbon it is used to with stand internal pressure of 3-25pa.
PROPELLANT GRAIN: It is the inner part of the rocket motor system. it is filled with free standing grains.
THERMAL INSULATION: It is the combustion part its range is around 1500-3000k to with stand this high temperature the design determines the selection of material and thickness in various areas.
THE IGNITION SYSTEM: This system brings the energy to the surface by the initiator booster charge &maincharge.
THE NOZZLE: This converts the
pressure into super sonic
exhaust by the convergent and
divergent sections depending
on this the speed depends
FLEXJOINT/FLEX SEAL:
As the movable nozzles are most efficient.
The seals are coated with natural rubber and this flex seal is coated with adeprene coating to avoid water soaking.
It uses deformation of doubly curved elastomeric layers between metal sheets to carry the loads and deflection.
This flexible seal nozzle are used in launch vehicles and strategic missiles.
ATTITUDE OF A MISSILE:
THRUST VECTOR CONTROL MECHANISM:
It is to control& guidance of the missile.
To compensate for flight disturbances & vehicle imperfections which will effect the missile attitude &stability
To acquire flight trajectory.
JET VANES & JET AVATOR & JET TABS:
This were used in tactical missiles, average thrust loss is small. The loss is high when rotated in full scale and the loss is less when rotated in small scale.
GIMBAL OR HINGE: Gimbal is a joint hinge permits to rotate in one direction engine is pivoted on a bearing
Measurement system
Measurement systems are normally used to record and display the signal from transducers.
It is used to find the overall system level requirements.
Data channels are used to transmit the data to data acquisition system.
Output is displayed in the form of analog as well as digital by using A/D converter and D/A converter.
SENSORS
A sensor is a device that measures a physical quantity and converts it into a signal.
Sensor's sensitivity indicates how much the sensor's output changes when the measured quantity changes.
A strain gauge is a device used to measure the strain of an object.
The gauge is attached to the object by a suitable adhesive, such as cyanoacrylate
Strain Gauge Transducer.
A strain gauge measures the external force (pressure) applied to a fine wire. The fine wire is usually arranged in the form of a grid. The pressure change causes a resistance change due to the distortion of the wire. The value of the pressure can be found by measuring the change in resistance of the wire grid.
Physical operation:
When an electrical conductor is stretched within the limits of its elasticity such that it does not break or permanently deform, it will become narrower and longer. Conversely, when a conductor is compressed such that it does not buckle, it will broaden and shorten.
Load Cell Operating Principles:
Load cell designs can be distinguished according to the type of output signal generated (pneumatic, hydraulic, electric) or according to the way they detect weight (bending, shear, compression, tension, etc.)