Experimental analysis of drag reduction in the pipelines with response surface methodology

Abstract

Abstract Obtaining fundamental variables has critical importance in solving engineering problems, and analysis of experimental data aids more-efficient experimentation. Drag reduction in pipelines is particularly useful in efforts to reduce energy losses. In the present study, statistical procedures are used to analyze some drag reduction experimental data to determine the degree to which each variable and its interactions with the others contribute to drag reduction. The experiments in this study incorporate parameters such as Reynolds number and temperature of fluid, concentration of different drag reducing agents and relative roughness of pipes. A proposed model has been developed by applying response surface methodology to historical data. The statistical analysis shows that the model is statistically acceptable ( R 2 =96.78%). Results of analysis show that 95% of variation in the friction factor can be described only by Reynolds number and concentration of drag reducing agent and their interactions. Finally for operational applications, a nomograph has been presented to evaluate friction factor simply.