Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
A FIRST-PRINCIPLES MODEL FOR AXIAL FANS: OPTIMIZATION RESULTS OF BLADE PITCH ANGLE
Submission Author:
Gabriel Podgaietsky , SC
Co-Authors:
Gabriel Podgaietsky, Christian Hermes, Adriano Francisco Ronzoni
Presenter: Gabriel Podgaietsky
doi://10.26678/ABCM.COBEM2021.COB2021-1126
Abstract
Aiming at designing more efficient components for refrigeration systems, a first-principles axial fan model is put forward in this paper, consisting of a discretization of the blade along the radial direction. At each element a sum of forces is performed considering the aerodynamic behavior of the blade section, besides the conservation of momentum. The resulting set of non-linear algebraic equations is solved iteratively through a sub-relaxation procedure. Numerical results based on an 8-inch 5-bladed condensing unit fan at 1350 RPM showed that the model reproduces well the head and shaft power trends observed experimentally, albeit overestimating these quantities within 10% and 20% bounds, respectively. To illustrate the model potential for design purposes, the pitch angle distribution of the baseline fan was optimized for 0 Pa and 10 Pa. The numerical results showed the optimized fans to be about 3% more efficient than the baseline one.
Keywords
Axial fan, modeling, blade element theory, pitch angle optimization, Characteristic curve
