Free & Forced Convection Phenomena Unit
(HT - 006)

1 Air duct. 2 Fan (to intake air into the air duct in case of forced air) (air outlet). 3 Strainer (to eliminate dusts) (air inlet). 4 Humidity sensor. 5 Inlet air temperature sensor. 6 Air speed sensor on a traversing mechanism to move the speed sensor easily. 7 Geometry. 8 Outlet air temperature sensor. 9 Heat transfer distribution points’ matrices. 10 Operation panel.

  • Energy Balance of Free Convection
  • Energy Balance of Forced Convection
  • Comparison of free and forced convection
  • Temperature Layering out at Heated Surface
  • Reynold’s Number
  • Nusselt Number
  • Coefficient of Heat Free / Forced Convection
  • Air Duct.
    • Cross-section: 120 x 150 mm2.
    • Height: 1 meter.
  • Heating Elements.
    • Power 200 watt.
    • Controlled (adjustable).
  • Axial Fan.
    • Maximum air speed: 3 m/s.
    • Controlled (adjustable).
    • Air flow entrance mesh.
  • Measuring Ranges.
    • Air velocity: 0…20m/s.
    • Temperature: 5x 0…350°C.
    • Heating power: 0…200 W.
  • Speed Sensor.
    • Working range
      • 0...10 m/s (0...2000 ft./min)
      • 0...15 m/s (0...3000 ft./min)
      • 0...20 m/s (0...4000 ft./min) (factory setting).
    • Temperature Range.
      • working temperature probe -25 ... +50 °C.
      • working temperature electronic -10 ...
        + 50 °C.
      • storage temperature -30 ... +60 °C.
      • Working range humidity: 5...95 % RH (non-condensing).
  • Humidity Sensor.
    • Working range: 10...95 % RH.
    • Operating temperature: -40...60 °C (-40...140 °F).
  • • Free & Forced Convection Phenomena Unit (HT - 006)
    • Hard copy user manual
    • BEDO Software
  • Laboratory PC

The free and forced convection phenomena unit is designed to allow a clear representation of free and forced convection phenomena, determining heat flux over three different heat transfer surfaces and displaying the heat distribution along the extended surfaces of various geometries.

                                     
  • The unit consists of air duct, a fan, three heat transfer geometries, air velocity meter, temperature sensors, digital displays, data acquisition system and control unit.
  • The air duct has a transparent front for visualizing the extended surfaces of the geometries during taking measurements.
  • The transparent front of the air duct has heat transfer distribution measuring holes to allow the trainee to insert the temperature sensor probe to measure the temperature at any point of the extended surface of the geometry.
  • The axial fan is mounted on the top of the duct to intake air into the air duct in case of forced air.
  • The unit is supplied with 3 heat transfer geometries that can be interchanged quickly and easily; flat plate, pin bundle surface and fins surface.
  • Each heat transfer geometry has its built-in heater.
  • The temperature sensors are used to measure the air temperature before and after the heat transfer geometry and the temperature of the extended surface of the heat transfer geometry.
  • The digital displays are used to measure inlet air temperature (at the air duct inlet), heater temperature, outlet air temperature (at the air duct outlet), humidity, air speed and heater power.
  • The air flow velocity through the air duct is measured using an air velocity sensor.
  • The control panel contains manual /software operation mode selection switch, fan operation and speed control knob, heater operation button, heater temperature control knob, heater power socket, socket of temperature sensor of heat transfer distribution points, on / off operation switch and emergency switch.
  • The educational unit is provided with a software that controls the unit and display the measured parameters.
  • The software can also record the results at an external PC›s drive.