University of Al-Qadisiyah Al-Qadisiyah Journal for Engineering Sciences 1998-4456 4 3 2011 09 28 Experimental study to reduce the hydraulic resistance of water turbulent flow in pipes by polymer additives دراسة تجريبية لتقليل المقاومة الهيدروليكية لجريان الماء الاضطرابي في الأنابيب بإضافة البوليميرات 0 0 32089 EN Journal Article 2011 09 01 The aim of this research is to study the effect of polymeric additives to water on friction coefficient change in a turbulent pipe flow which would cause in reduction of drag resistance. Experiment is done using the polyacrylamide ( PAM ) as polymeric additive to show the effect of addition of ( PAM ) with case low concentrations (0.005,0.013 , 0.025%) on the friction factor (λ) . The results show that the addition of (PAM) will reduce (λ) with a range from 6.51 to 37.95% comparable with the friction coefficient (λ) for water before addition in a turbulent flow case. Also a study of the addition effect of ( PAM ) with different concentrations between ( 0.005 – 0.06% ) on the reduction percent of (λ) is carried out . The results show increasing the effect of the addition (PAM ) cause in increasing the reduction percent Δλ / λ % with a range of 6.51 to 44.62% . It is found that the peak values called the optimum values)Cp*(of PAM between 0.03&0.042. Increasing the addition of PAM cause in decreasing the effect of reduction percent with concentrations at several Reynolds number as follows: ( Re = 25350 & 0.03%, Re = 28355& 0.033 % , Re=34981&0.038 % , Re=39360 & 0.039% , Re=44985 &0.042%). https://qjes.qu.edu.iq/article_32089_e8792705b5cea2f03388f86885f645a3.pdf