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Variation in product performance can be seen as a design failure. The fundamental principle of robust design proposed by Taguchi is to improve the quality of a product by minimizing the effect of causes of variation, without totally eliminating the causes. A method of robust design is briefly explained and its application is demonstrated with the help of a case study from Roots Industries Ltd., Coimbatore. This paper describes how the inherent modeling of product and process requirements in key characteristics (KCs) can be used to express and capture the product design intent. KCs are those features which significantly affect product function and performance, or occur when there is variation. A prototype software program (VRM Tool) was developed to house all the critical design data for process optimization and its eventual reuse. We establish a systematic process of identifying, assessing and mitigating risk in the early stage of design for a Windtone class of automobile electric horn, using robust design concept. The results suggest that the proposed robust design method is an efficient, disciplined approach that can assist a product delivery team in designing for a better functional performance and improved reliability of the entire system.

This paper illustrates the improvement in the performance of a centrifugal pump by modifying impeller design specifications via response surface methodology (RSM) complemented with computational fluid dynamics (CFD) simulations. Impeller geometry is varied at the best efficiency point (BEP) to get hold of the performance of the pump. The pump characteristics are evaluated by studying the impeller eye diameter, vane exit angle, and width of impeller blade at exit. Different pump models were analyzed by modifying the critical design parameters via central composite design. CFD analysis is carried out for the developed models to predict the performance of the pump and experimental studies were conducted to validate the CFD. Conformation experiments were performed to verify the optimal design specifications. Good agreements between the predicted and actual values of responses have been observed. The RSM-and CFD-based optimized impeller parameters yield an increase in total head from 39.66 m to 41.72 m and the power consumption is minimized from 432.17 W to 366.95 W at BEP.

This article discusses a research methodology for performance enhancement of centrifugal pump through Taguchi's parametric design concept. The objective is to find an optimum impeller design and geometry that makes the pump functionally reliable for winning customer's confidence. Computational fluid dynamic (CFD) analysis has been done to know how the flow pattern changes in the impeller when the pump is required to run at different operating conditions. The streamline analysis from CFD plots gives informative pictures of the flow field, which help the designer understand how the effect of deviation made in the impeller design specifications significantly influence the pump performance. CFD results match well with the predictions of the pump performance at the duty point as regard to head, discharge, and efficiency of the prototype model. The study infers that the CFD prediction tallies with Taguchi's experimental results.Keywords: pump impeller, performance enhancement, orthogonal array, design of experiments, signal-noise ratio, analysis of variance, response analysis, computational fluid dynamic analysis LITERATURE REVIEWThe design of hydraulic machinery involves a lot of parameters that are interdependent and, in turn, iterative, which makes the problem at hand more complex for the human brain to manipulate [1 -3]. However, the innovation in computational fluid dynamic (CFD) field has made it possible to simulate and visualize some of the features of flow through rotating machines that would be difficult to measure experimentally [4 -8]. The importance of pumps in hydraulic field had been sensed by mankind over the 20th and 21st centuries (see References). The global market of today is flooded with plenty of varieties, types, and sizes of pumps. In spite of its age, even today the design of pumps has not attained the saturation stage. In fact, pump design compatible with the production environment had been a major challenge to researchers. Particularly, researchers along with engineers had been striving to improve the design of impellers with the specific attention directed to enabling the enhancement of pump performance [9 -11]. Li [12] formulated a method for analysing the performance of centrifugal oil pump, whereas Li et al. [13] analysed in their work the influence of a number of impeller blades on the performance of centrifugal oil pumps.Performance prediction procedures for centrifugal and axial flow turbomachines have been widely published by several researchers [14-18] since the early days of turbomachine design, whereas those for mixed flow machines are not well established in the open literature because of the industrial sources being classified as competition-sensitive by every industry. Sarkar [19,20] presented the performance prediction method for a mixed flow impeller on the basis of the two-dimensional cascade theory, extending Howell's [14] calculation for the analysis of axial Ã