APPLIED FLUID MECHANICS
C1-MkIII Compressible Flow Unit – Provisional
A versatile apparatus, based around a variable-speed air compressor, designed to teach the concepts of compressible flow. The basic unit contains everything required to demonstrate the fundamental principles, but an accessory (C1-MkIII-30) is available containing a number of interchangeable test sections to give a wider knowledge and understanding to the student.
A further accessory (C1-MkIII-35) allows full compressor performance and characterisation tests to be carried out.
- A benchtop unit designed to demonstrate and teach the fundamentals of compressible flow to engineering students
- Fitted with a single-stage, side-channel blower
- Complete with convergent-divergent duct capable of achieving Mach 1 velocity at the throat
- Advanced torque-vector speed control of blower motor with electronic torque measurement
- Four electronic pressure sensors
- Test section made from clear acrylic
- Additional test sections available (6 off) complete with benchtop stand
- Compressor test accessory available
- Data logging accessory available, complete with educational software and electronic temperature sensors
- Variable-speed air compressor with accurate electronic speed control
- Electronic pressure sensors
- Standard unit includes convergent-divergent duct designed to produce Mach 1 velocity at the throat
- Data logging option available
The air compressor on the MkIII version comprises a single-stage, side-channel blower with the following benefits:
- Lower speed operation
- Integral motor with direct drive
- Reduced operating noise
- Reduced vibration levels
The C1-MkIII equipment comprises a single-stage air compressor, complete with a test section and a throttling valve, plus an electronics console containing the necessary controls and instrumentation.
The single-stage compressor is driven by an integral three-phase AC motor. The compressor speed can be varied using an advanced torque-vector frequency inverter, which gives stable and accurate speed control plus direct electronic read-out of the torque produced by the motor. The compressor is fitted with an outlet duct incorporating a throttling valve, which allows the flow to be varied independent from compressor speed.
Convergent-divergent test section
The equipment is supplied with a convergent-divergent test section, fitted at the compressor inlet, designed to produce Mach-1 velocity at the throat. The duct is fabricated from clear acrylic, enabling the student to see the construction and the profiles. A pressure-sensing ring tapping is provided at the inlet, at the throat and at the discharge end of the diffuser. This duct allows all the major concepts of compressible flow to be demonstrated.
The electronics console includes two high-range and two low-range differential pressure sensors plus a control for motor speed and displays for the compressor speed, the pressures and the motor torque.
Basic unit (C1-MkIII):
- Phenomenon of choking in a convergent-divergent duct
- Pressure flow characteristic of a convergent-divergent duct
- Effect of compressibility on flow equations
- Determination of gamma for air
Added capability with C1-MkIII-30 accessory:
- Simple pipe friction
- Variation of friction coefficient with Reynolds number
- Friction coefficient for compressible flow
- Pressure recovery across a sudden enlargement
- Pressure drop across a pipeline orifice
- Pressure drop across a 90° bend
Added capability with C1-MkIII-35 accessory:
- Centrifugal compressor performance characteristics
- Energy balance for compressor
C1-MkIII-30 Additional Test Sections
The C1-MkIII-30 option includes additional inlet test sections for further demonstrations and investigations into compressible flow. The test sections are made from clear acrylic to aid visualisation and fitted with pressure-sensing ring tappings.
This accessory includes a bench stand to house all the accessories (plus the standard test section and the C1-MkIII-35 test section) when these are not being used.
Additional sections provided:
Three straight ducts of different diameters, to allow pressure losses incurred in a straight pipe to be studied in relation to Reynolds number.
A sudden enlargement section
A 34mm nominal bore test section with four interchangeable orifice plates.
A 90° bend test section. Provision is made to investigate the radial pressure difference across the bend
C1-MKIIi-35 Compressor Test Accessory
The C1-MkIII-35 option comprises a test section to measure the air flow entering the compressor. This facility, in conjunction with the electronic torque measurement and thermometers on the basic C1-MkIII, allows full compressor performance tests to be conducted over a wide range of shaft speeds.
C1-MkIII-DTA-ALITE includes electronic thermometers and a computer interface device to allow the temperatures and pressures to be data logged on a Windows PC.
The advanced educational software provides a wide range of data logging and plotting options. A personal computer running Windows, with a spare USB port, is required (not supplied by Armfield).
C1-MkIII-A: 220-240V / 1ph / 50Hz, 6A
C1-MkIII-G: 220-240V / 1ph / 60Hz, 6A
A 1500VA transformer is available to accommodate 120V / 1ph / 60Hz
A PC running Windows XP or above with a spare USB port (not supplied by Armfield).
|Compressor speed:||3,300rpm (max)|
|Sensors:||+/- 103.4kPa 1 off|
|-||+/- 34kPa 1 off|
|-||+/- 1744Pa 2 off|
C1-MkIII-A: 220-240V / 1ph / 50Hz, 6 amp
C1-MkIII-G: 220-240V / 1ph / 60Hz, 6 amp
TRANSFORMER-1500VA 120V / 1ph / 60Hz