Kenan Yakut

Reduction of Peak Amplitudes of Pressure Fluctuation in Turbulent Pipe Flow Using Vortex Generators and Compliant Boundaries

The effects of vortex generators and compliant boundaries on the reduction of peak amplitudes of pressure fluctuations in a turbulent pipe flow were investigated experimentally. They had important effects on the reduction of peak amplitudes of pressure fluctuations in the model experimental pipe system containing two orifices. The vortex generators having an alternating angle were more effective than the compliant boundaries.

Numerical analysis with experimental comparison in duct flow using optimized heat sinks

Abstract In many industrial applications, heat must be transferred in the form of either an energy input into the system or removal of energy produced in the system. In this study, heat transfer and flow characteristics of hexagonal finned heat sinks which optimized according to the Taguchi experimental L18(21*37) design method in channel flow was analyzed numerically. Ansys-Fluent Icepak module was used in CFD analysis. The analysis carried out for two hexagonal finned optimized heat sinks in 3 different fin heights and 5 different flow velocities. Nusselt number increased with increasing Reynolds number for OH-1 and OH-2 heat sinks with all fin heights. Also, results showed that the friction factor decreased with increasing Reynolds number for all fin heights. According to CFD results, Nu-Re and f-Re variations were obtained and compared with experimental results. The experimental results and the numerical results were quite consistent.

Determination of Heat and Flow Characteristics in Spray Cooling with Rectangular Finned Heat Sink

This research was supported as project (BAP-2013/103) of the Research Fund of Ataturk University.

Analysis of Heat and Flow Characteristics on Spray Cooling Heat Transfer with an Optimized Hexagonal Finned Heat Sink

An experimental study was carried out with a hexagonal finned heat sink to obtain valuable information about the thermal and flow characteristics on spray cooling. Water was used as the refrigerant fluid and was atomized by an air-assisted atomizer and some of the variables that affect spray cooling process, such as breakup length and Sauter Mean Diameter (SMD) were obtained using appropriate correlations. The parameters most influential on the Nusselt number were determined and analyzed. Experiments were conducted for optimized conditions. The jet diameter and spray angle were determined via image processing using macroscopic aspects. Nusselt were demonstrated of hexagonal finned heat sink which optimized according to the Taguchi optimization method. The results of the spray analysis showed that SMD decreases with an increase in either air-liquid mass ratio (ALR) or operating pressure resulting in a more uniform spray. As the liquid flow rate increases in all ALR values, the heat transfer rate also increases markedly. As a results of the experiments, Nusselt number, jet width and spray angle correlations were developed. The relationship of ALR-Nu was demonstrated according to fin height and spraying time.

Thermal performance analysis of optimized hexagonal finned heat sinks in impinging air jet

In this study, thermal performance analysis of hexagonal finned heat sinks which optimized according to the experimental design and optimization method of Taguchi were investigated. Experiments of air jet impingement on heated hexagonal finned heat sinks were carried out adhering to the L18(21*36) orthogonal array test plan. Optimum geometries were determined and named OH-1, OH-2. Enhancement efficiency with the first law of thermodynamics was analyzed for optimized heat sinks with 100, 150, 200 mm heights of hexagonal fin. Nusselt correlations were found out and variations of enhancement efficiency with Reynolds number presented in η–Re graphics.