Novel management of transducer heat and nonlinearity

Ferro Solutions and Carnegie Mellon University propose to develop a novel technology for management of transducer heat and nonlinearity. Non-linear transducer response generates excessive heat and thus reduced efficiency in the transducer. Higher frequencies in the acoustic signal are more strongly absorbed and this leads to reduced range in the acoustic signal. we have designed a novel and efficient self-pumping, cooling cycle based on a fluid filled with small magnetic particles. Ultimately, these would be either Fe-Ni or giant magnetocaloric nano-particles The composition of the particles is designed so that their Curie temperature lies between that of the heat sink and the acceptable upper operating temperature of the transducer.The self-pumping action is due to the fact that the colder, ferromagnetic particles are attracted to the high magnetic field region near one end of the transducer (heat load), and the heated, paramagnetic particles are not drawn back as they leave the magnetic field near the transducer. The heated particles drive the fluid flow and their net heat content is delivered to the cold reservoir. Calculations indicate that this system should drive the magnetic fluid at close to 10 cm/sec giving cooling rates of about 1kW per10 cm-long, 1 cm2-diameter cooing channel in the transducer.