Heat Transfer Enhancement of Drag Reducing Surfactants Using Ultrasonic Energy

Surfactants have the ability to reduce drag in pipe flow by as much as 80%, thereby yielding considerable pumping costs savings for applications such as district heating and cooling systems. However, one significant drawback of using surfactants for district heating and cooling systems is that heat transfer ability of the solution is greatly reduced. This project studies the novel, non-intrusive technique of applying ultrasonic energy to degrade the surfactant micelles before entering the heat exchanger to obtain optimum heat transfer and drag reduction. Upon exiting the heat exchanger, the surfactants reconstruct themselves and, once again, exhibit a drag reduction effect. An alternative method to achieve drag reduction is also studied by ejecting microbubbles into the flow system to dampen turbulence and eddies emerging from the wall region of the pipe. A patent pending Gas Ejector is concieved and used as an economical and practical device for microbubble drag reduction applications.