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NEED help with AFR control project

  1. Jun 2, 2012 #1
    Hi everyone im new here!
    and i desperately need help..
    Im making an AIR to FUEL ratio control system for IC engine...its a project i started working on but i have a deadline in almost 3 weeks...
    the layout is simple...theres airflow on one side and fuel flow on the other side..
    both of the flows are sensed the air by a suitable air flow meter or any device that can sense the mass flow rate or volume flow rate, and on the fuel side a suitable fluid flow sensor...

    both these inputs are fed to a microcontroller and this will formulate the input data in a useful form and match it with the required AFR for our engine...if AFR is low then the mass of air should be increased so the mcu will command an actuator to increase the flow rate of air
    OR/AND command another actuator to decrease flow through the fuel duct similarly....
    the problem is that this is supposed to be a very small scale project and creating these phenomena s of air flow and fluid flow on a very small scale is becoming very difficult...

    we tried choosing a small fan to drive air by varying the voltage we could vary the rpm of it..but we had decided to put another fan right infront of it that will rotate because of air flowing through it and in turm generate a pd across its terminals that we'll feed into the mcu...however our fan doesnt even rotate air from a large fan or wind...its impossible to rotate it with a fan smilar to its size...

    for controlling and measuring the fluid flow we thought we'll use a butterfly valve with a stepper motor connected to its shaft and take the input in the form of 'theta' ( at 0 degress ther will be minimum or 0 flow and at 90 degrees there will be complete or maximum flow)
    but the setup and everything is very large and itll be hard to manage our circuitry and interfacing at the same time since this is our first time making a real project as second year aerospace students...
    any ideas? how do i go about this?? :( :(
  2. jcsd
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