Numerical investigation of the parameters effecting onradial fan performance

Fans have an important place in industrial applications. With the help of fans, the mechanical energy is converted to the pressure difference in the fluid and the air flow is provided. They are generally divided into two groups as axial and radial fans. The radial fans serve in a wide range of flow, pressure and power in many areas of the industry. In this study, a household type aspirator radial fan which holds an important place in industrial applications is analyzed. The forward curved radial fan is considered in the study. As the independent parameters, the angle of the wing inlet, the angle of the wing outlet, the number of wings, wing thickness, rotor outer diameter and wing height were determined. Angles of the wing inlet and wing outlet were between 120°-170° are 60°-120°, respectively. The wing numbers and wing thickness are changed between 40-60 and 0.8-1.4 mm respectively. The rotor outer diameter is changed as 140-160 mm. Also analysis was made for wing height in the range of 8-12 mm. The effects of these independent parameters on air flow, fan outlet pressure, torque and fan efficiency were investigated. The study was done numerically by Computational Fluid Dynamics (HAD). ANSYS CFX package program was used for this purpose. As it is known, CFX software provides highly accurate results on numerical analysis of turbomachinery. Three different types of turbulence models were applied to determine the appropriate solution and the k𝜖model provides the most accurate results. Therefore, k-𝜖turbulence model is used in the solution. Experimental findings were used to prove the accuracy of numerical modeling. The same radial fan was produced in a 3D printer and was tested according to the Air Movement and Control Association (AMCA). The experimental data in terms of pressure and flow rate were determined at 1500 rpm. In numerical modeling, the solution algorithm and the appropriate number of grids were determined for providing the data obtained from the experimental findings were determined. In the grid optimization, it is determined that the number of grids of about 4,5 million is the optimum value. Based on this solution algorithm and grid value, it was found that the difference was less than 4% with experimental findings. In order to keep the solution process short and to analyze the results correctly, appropriate experimental design method based on Response Surface Method was used. ANOVA analysis was performed to ensure the accuracy of the findings obtained from this method. The results of high regression coefficient and small p value were determined. In the results obtained, it was determined that the most effective parameter for mass flow rate, pressure, efficiency and moment is the wing outlet angle. However, it has been found that especially the outer diameter of the rotor and the wing height significantly affects the dependent parameters. In addition to the single parameters, depending on the combination of dependent parameters, it was determined that the outer diameter of the rotor together with the wing outlet angle, the wing inlet angle together with the wing outlet angle, the number of the wings together with the wing height were effective on the dependent parameters.