Aerodynamics
Sarallah Abbasi; Ali Joodaki
Abstract
In This paper, a parametric study of compressor performances was performed by streamline curvature method (SLC). Effects of three input parameters in design process, e.g., number of blades, distribution of blade thickness, and blade sweep angels, on the main objective parameters in aerodynamic design, ...
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In This paper, a parametric study of compressor performances was performed by streamline curvature method (SLC). Effects of three input parameters in design process, e.g., number of blades, distribution of blade thickness, and blade sweep angels, on the main objective parameters in aerodynamic design, e.g., velocity distribution, efficiency and pressure ratio, has been investigated in the parametric study. Initially, a certain two stage axial compressor has been designed by SLC. Validation of the results is confirmed by comparing the obtained results with the experimental ones. Regarding various values for aforementioned input parameters, the first stage of the axial compressor is redesigned and the output parameter is established. Therefore, the sensitivity of the design results to each of the aforementioned parameters is recognized. Results show that increasing the blades sweep angle causes to improve the flow behavior such as efficiency and pressure ratio in axial fan and reducing it have a completely contrary result. Also, reducing the rotors blades number leads to an increase in the pressure ratio and efficiency while its increase cause to a contrary result. , it is concluded that reduction in the blades number has the stronger effect on the performance parameters than its increment. The results also show that effect of the thickness in the hub is greater than the thickness of the tip and its increase leads to reduce both efficiency and pressure ratio.
Compressible Flow
Sarallah Abbasi; ali joodaki
Abstract
The choice of geometrical shape of the blades has a considerable effect on aerodynamic performance and flow characteristics in axial compressors. In this paper, the effects of the blades shape on the aerodynamic design characteristics are investigated based on Streamline Curvature Method (SCM). Initially, ...
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The choice of geometrical shape of the blades has a considerable effect on aerodynamic performance and flow characteristics in axial compressors. In this paper, the effects of the blades shape on the aerodynamic design characteristics are investigated based on Streamline Curvature Method (SCM). Initially, the Streamline Curvature Method (SCM) is used for designing a two-stage axial compressor. Comparing the current results with experimental ones indicates good agreement. The first stage of the axial compressor is selected with three different blade profiles. The first case (case I) has the polynomial camber with naca thickness distribution series 6. The second case (case II) has the standard naca profile series 6 and the third case (case III) has the modified standard naca profile series 4. Results reveal that using the standard airfoils in the stators leads to improved flow conditions such as loss coefficient and pressure ratio. On the contrary, this profile selection may cause an increase in the stagger angle that is not favorable. Aerodynamic Design with a polynomial camber line in the rotor demonstrates a better aerodynamic behavior in loss coefficient, pressure ratio and diffusion factor. Whilst the use of such a camber line in the stator leads to the formation of less favorable aerodynamics conditions in comparison to the standard airfoil.
