دراسة عملية لتأثير الإهتزازات في معامل انتقال الحرارة بالحمل القسري

الملخص EN

The aim of this work is to perform an experimental study for the effect of forced vertical vibrations on forced convection heat transfer coefficient, by the use of circumferential finned cylinder made of Aluminum.

The cylinder was heated under the condition of a constant heat flux which is generated by applying an alternating voltage on a fixed resistor mounted inside the interior space of the cylinder which was located horizontally or inclined in multiple angles at a range of (0°-45°).

In this experimental study the circumferential finned cylinder prototype of inner diameter (16 mm), and outer diameter including the fin of (48 mm), and the effect of the frequency at the range of (2-16 Hz) and the vibration amplitude range of (0 - 2.2mm) have been studied with various heat flux range from (500-1500W/m2).For the results of this study it was found that the relation between the heat transfer coefficient and amplitude of vibration is incrementally for all inclination angles from (0°-45°), and reaches a maximum ratio of (%13.34), also increment of inclination angle reduces the values of forced convection heat transfer coefficient and , that because the fins works as path lines helps to increase the movement of convection currents in the case of horizontal prototype , but in case of inclined cylinder fins works as obstructions for the convection currents and thus reduces the ranges of forced convection vibrational heat transfer coefficient, Generally the heat transfer coefficient increases as Reynolds number increases