چكيده به لاتين
With the advancement of technology and reduce of equipment size, as well as increasing power and productivity, the need for high flux heat transfer in small area is a necessary, nowadays. One of the newest technologies in this field is oscillating heat pipes that allows high flux heat transfer. The oscillating heat pipe is a high-efficiency two-phase heat transfer device, first proposed by Akachi in 1990. Although the oscillating heat pipes are a subclass of the family of thermal pipes, this type offers new features than traditional ones. Their structure consists of a long tube with a condenser and evaporator that is located on both ends sides. The possible mechanisms for heat transfer is heat absorption to increase the temperature, as well as the working fluid phase change. Simple and inexpensive structure, fast thermal reaction and high heat transfer ability make this type of heat pipe very attractive.
In this thesies, the effect of inclination angle and filling ratio on the heat transfer characteristics and resistance of an oscillating heat pipe constructed partly by copper and glass containing graphene nanoparticles has been investigated. The results of this experimentally investigation shows that in general, by having water as working fluid, approaching the vertical angles, when heater is blow the condenser, the performance of the device is better while increasing the filling ratio can improve the heat conductivity in all cases specifically in the horizontal / close to the horizon inclinations. In case of usage of graphene-water nanofluid as working fluid, the highest improvement was achieved with 60% filling ratio, but the best heat transfer performance was observed in 80% filling ratio. Also, in higher filling ratios, inclination angles near the horizon showed better improvements in heat transfer conductivity in the case of using nanofluid.
