Optimization of Location of Magnet on Multiple Piezoelectric-Magnetic Fan (MPMF) using Design Expert

Abstract

A cooling system based on piezoelectric fan is proven to have a potential solution for cooling small electronic devices for its advantages of light weight, small power consumption, less noise and space efficient. A multiple piezoelectric-magnetic fans (MPMF) was introduced to enlarge the cooling coverage area and enhanced by optimizing the location of magnet on the fan blade and distance between magnet to length ratio using Design Expert (DE) software. As a result, the best location of magnet with respect to the total length of the fan is 63.17% which is $43.~58\mathrm {m}\mathrm {m}$ from the origin of the fan with frequency of $43.~05\mathrm {H}\mathrm {z}$ and the velocity of air generated at the tip of the fan is $1.~6\mathrm {m}/\mathrm {s}$. The effect of magnet can only be realized when double or multiple fans are applied. The distance between magnet to length ratio is 23.93% which is $16.~5\mathrm {m}\mathrm {m}$ with average velocity of $1.32~\mathrm {m}/\mathrm {s}$. The deflection at this moment is $9.~3\mathrm {m}\mathrm {m}$. Even though MPMF generated smaller air velocity, it covered bigger area $(1049\mathrm {m}\mathrm {m}^{2})$ compared to single fan ($322.6~\mathrm {m}\mathrm {m}^{2})$. Optimum stiffness is required to ensure the fans are oscillating at high frequency and deflection to obtain the maximum velocity of air at the tip of the fan. The RPMF is better than APMF with optimum magnetic stiffness of $79~\mathrm {W}/\mathrm {m}\mathrm {K}.$