Application of a central composite face-centered design in the optimization of an Archimedean hydrokinetic turbine

Abstract

Currently, in the literature, there are no general guidelines for the optimal hydraulic design of Archimedean screw turbines (AST) used in hydrokinetic applications. Therefore, this study is aiming at selecting the most significant geometric factors, such as the diameter ratio between the inner (𝐷𝑖 ) and the outer (𝐷𝑜) diameters (i.e., 𝐷𝑖/𝐷𝑜), the axle length (𝐿) and the blade stride (𝑝), influencing the AST performance by using a central composite face-centered (CCF) experimental design combined with the response surface methodology (RSM). The statistical analysis of variance (ANOVA) test identified with a significance level of 0.05 that the most significant variables on the performance of the turbine were 𝑝 and 𝐷𝑖/𝐷𝑜. The AST efficiency was evaluated by means of the power coefficient (𝐶𝑃), which was calculated by means of computational fluid dynamics (CFD) methods coupled with the 6-degrees of freedom (6-DoF) approach. The second-order polynomial model was used to predict the 𝐶𝑃 and the coefficient of determination (𝑅 2 ) was found to be 97.4%.

Graphene in rubber formulations: a comprehensive review and performance optimization insights

“…202 Diagnostic graphs such as normality plots, residual vs. predicted graphs, predicted vs. actual graphs, and more are presented in the analysis of variance. 203 The 2D contour plot and 3D surface plot are generated after the analysis and screening process in the analysis of variance. 204 In the optimization process, the input variables and output response are adjusted according to the requirement of the research.…”

CFD modelling of a wave-mixed bioreactor with complex geometry and two degrees of freedom motion

“…By using formula N = 2 k + 2k + cp with k as the number of factors and cp as the number of center points, 15 simulations per geometry were obtained (since no variation in results is expected when simulating at the center point, cp = 1) (Ranade and Thiagarajan, 2017). The CCF design allows data to be fitted to a complete quadratic model and is widely used both in the general literature as well as in the field of CFD (Wang et al, 2018;Betancour et al, 2021;Kaur et al, 2022;Murillo et al, 2022).…”

Generation of Electricity From a Hydraulic Turbine in the Djonou River (Benin)

“…In order to improve the performance of this technology, several investigations have been carried out in the literature. In the work of Yulistiyanto et al [20], Maulana et al [13], Alkistis et al [19], Maulana et al [15], Abdul et al [9], Khan et al [21], Betancour et al [22], Abdillah et al [23], Imawati et al [24], Eswanto et al [25], Erinofiardi et al [26] the authors studied the influence of the geometric and hydraulic parameters of the Archimedes screw, namely the angle of inclination of the shaft, the number of blades, the variations in flow, the slope of the shaft , the direction of the axis of rotation, the speed of rotation, its angle of slope, the diameter ratio between the inner and outer diameters, the length of the axis and the pitch on the power and efficiency of the screw. According to the work of Warjito et al [6], the authors believe that the Archimedes turbine has no fixed design theory.…”