International Journal of Engineering Trends and Technology Volume 70 Issue 2, 137-142, February, 2022 ISSN: 2231 – 5381 /doi: 10.14445/22315381/IJETT-V70I2P216 © 2022 Seventh Sense Research Group® This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Original Article Experimental Investigations of Jet Expansion for Hydraulic Nozzles of Different Materials Hemal Lakdawala 1 , Akshay Gupta 2 , Vimal Patel 3 , Hitesh Jariwala 4 , Gaurang Chaudhari 5 1 Assistant Professor, Government Engineering College, Valsad, Gujarat, India 2 Associate Professor, Sitarambhai Naranji Patel Institute of Technology & Research Centre, Umrakh, Surat, Gujarat, India 3 Assistant Professor, S. V. National Institute of Technology, Surat, Gujarat, India 4 Head of Department, J. H. Desai Polytechnic, Palsana, Surat, Gujarat, India 5 Assistant Professor, C. K. Pithawala College of Engineering & Technolgy, Surat, Gujarat, India 1 hnlakdawala@gecv.ac.in, 2 akshaygupta2406@gmail.com, 4 jariwala_hiteshkumar@gtu.edu.in Abstract — A nozzle is an essential part of fluid and pneumatic system to increase or decrease kinetic energy of fluid at the expense of pressure. The convergent-divergent nozzle is most commonly employed in flow measurement, rocket propulsion systems, jet pumps, hydraulic turbines, etc. A convergent type nozzle solely is more useful in the case of a hydraulic system compared to a diffuser type. In the present study, nozzles with different materials and different exit diameters have been investigated. The effect of varying discharge on jet expansion for the same material with different exit diameters as well as different materials for the identical diameter is also studied. More robust the construction and jet with a smaller diameter is stable enough. For a stable jet, the standoff distance is more otherwise. Spreading of jet leads to loss of kinetic energy as air-entrained at the circumference in the free surface of jet. For the nozzle with 17mm diameter but with different materials, more discharge was found in the case with polymer nozzle, whereas less angle of jet expansion was found with stainless steel nozzle. The jet expansion was found more with a larger diameter nozzle for both stainless steel and polymer. With smaller diameter nozzles of 17 mm, it is likely for jet expansion. Keywords — Nozzle, Coefficient of discharge, Jet expansion, Material, Nozzle size, Jet quality. I. INTRODUCTION Nozzles have been employed in almost so many engineering applications since the advent of engineering and technological advancement. It eases the work by accelerating or decelerating the fluid with a change in either pressure or kinetic energy [1]. In an automobile, fluid power sector, various misting processes, sprinklers, injection system of automobiles, the propulsion system of rocket engine so many and so forth everywhere nozzles are used since it is a simple geometry involves no moving parts. Even in pneumatic and hydraulic systems for automation, it is a critical part as based on this feedback is sent to the controlling unit. In the present study, convergent fluid nozzles are taken under consideration, having a constriction ratio less than 0.5 as it is a useful part of a fluid power system. A thorough understanding makes more efficient use of nozzles in the fluid power section. Here convergent nozzles of different materials are taken under consideration and studied for high head, high Reynolds number and high discharge conditions. The quality of the jet depends on exit conditions, shape or opening velocity, a viscosity of the fluid and surrounding air at an application where the jet is to be employed [2], [3]. A jet issued from the convergent nozzle is studied to bring more clarity about work done. Benedict and Wyler [4] carried out analytical and theoretical studies of ASME flow nozzles in the early 80s, and correlations were established for various pressure tapped nozzles. Rahman et al. [5] and Alam et al. [6] have performed rigorous experimental investigations and stated that for different types of nozzle geometry and curvature, angle affects the end conditions; consequently, contraction of streamlines and the coefficient of discharge get affected. McCarthy and Molloy [7] have stated that by experimentation, the breakup pattern of liquid jets in regimes beyond the surface tension controlled axisymmetric case requires application-based correlations due to the complex nature of the flow. Cui et al. [8] found that smaller-diameter nozzles induce cavitation and hydraulic flip much more easily than larger-diameter ones. In a nozzle with a 10% smaller diameter, the critical pressure Pcrit required for inducing cavitation and hydraulic flip decreases by approximately 5.9% and 7.5%, and it will further decrease by 14.7% and 12.5% with a 20% smaller diameter. Kiaoulias et al. [9] carried out and found large diameters had small laminar flow jet breakup length, but large for turbulent and Sharp-edge inlets experienced cavitation and varying discharge coefficients. Essien et al. [10] carried out experiments and concluded that the value of maximum Cd for a given flow rate is relative to the flow area used. The coefficient of discharge (Cd) increased with the increasing value of the l/d ratio. Increasing the beta ratio led to a decrease in Cd. The effect of viscosity was