RTFM (2018) 1-11 © STM Journals 2018. All Rights Reserved Page 1 Recent Trends in Fluid Mechanics ISSN: 2455-1961 (Online) Volume 5, Issue 3 www.stmjournals.com Turbulence Modelling for Estimation of Hydraulic Jump Height Suresh Kumar N.*, Prasanna S.V.S.N.D.L. Department of Civil Engineering, College of Engineering (A), Osmania University, Hyderabad, Telangana, India Abstract The simulation plays an important role in understanding the behavior of the flow field that becomes difficult through experimental analysis. The present work focuses on the experimental studies carried out for different discharges ranging from 9.8 lps to 12.5 lps. The gate openings adopted for the study are 0.025 m at a slope of 1:1200 and 0.023 m at a slope of 1:857 and 1:705.8. The simulations were extended to determine the length and height of the jump by adopting user defined functions. The programme was executed in the fluent solver in order to obtain all the ‘X’, ‘Y’ and volume fraction values at all the cells downstream of the gate. The simulated values of height and length of the jump for the selected discharges are in agreement with the experimental results as well as analytical calculations. Keywords: Hydraulic jump, simulation, fluent, volume fraction *Author for Correspondence E-mail: nskdr@yahoo.co.in INTRODUCTION The modeling techniques help in analysis and simulation of various civil engineering problems. Flow fields that are difficult to comprehend through experimental analysis, can be easily understood by simulation. In addition, the physical modeling involves huge expenditure. Hence, the modeling techniques contribute to a large extent to study the effect and significance of diverse turbulence properties. The hydraulic jump is basically a type of rapidly varied flow that occurs in open channels. Hydraulic jump is said to form when the flow suddenly changes its form from super critical state to subcritical state. The entire hydraulic jump portion is taken as the control volume for the analysis of any extensive property like mass, momentum, etc. of flow phenomenon and the continuum equations are solved by adopting Reynolds Transport theorem. In the analysis of hydraulic jump, it is interesting to recognize the relationship between various characteristics viz., initial and sequent depths, air entrainment and large amount of energy that gets dissipated. The flow distinctiveness can be provided through numerical techniques without resorting to experimental investigations. Further, the accompanied energy and turbulence can be analyzed by means of latest numerical simulations [1]. In view of the application of hydraulic jump in a wide variety of flow problems viz., dissipation of energy of water flowing over dams and weirs – to prevent possible erosion and scouring due to high velocities, raising water levels on the downstream side of the flume to enhance flow depth for irrigation practices, reducing the uplift pressure under the foundations of hydraulic structures by raising the water depth on the apron, creating special flow conditions to meet certain special needs at control sections, and to aerate water for city water supplies. Hence, the present investigation was carried out with the following objectives.  Estimate the type, length and height of the jump analytically and experimentally.  Simulate and validate the experimental results adopting numerical modeling technique viz., ANSYS-CFD (Fluent) software. REVIEW OF LITERATURE The modeling techniques help in analysis and simulation of various civil engineering