Dynamic Analysis of Composite Propeller of Ship Using FEA

Transcription

1 ISSN , Vol. 2, No. 5, September 23, pp. 5 Dynamic Analysis of Composite Propeller of Ship Using FEA V.D.RAJESWARI.SWARNA, G.BALAKRISHNA 2 P.G Student, Mechanical Department, PVPSIT, Vijayawada, India 2 Assistance Professor, Mechanical Department, PVPSIT, Vijayawada, India vd.rajeswari@gmail.com Abstract: Ships and underwater vehicles like submarine and torpedoes use propeller for propulsion. In general, propellers are used as propulsors and they are also used to develop significant thrust to propel the vehicle at its operational speed and RPM. The blade geometry and design are more complex involving many controlling parameters. Propeller with conventional isotropic materials creates more vibration and noise in its rotation. It is undesirable in stealth point of view. In current years the increased need for light weight structural element with acoustic insulation has led to use of fiber reinforced multi layered composite propeller. The present work is to carry out the dynamic analysis of aluminum, composite propeller which is a combination of GFRP (Glass Fiber Reinforced Plastics) and CFRP (Carbon Fiber Reinforced Plastics) materials. The present thesis deals with modeling and analyzing the propeller blade of a underwater vehicle for their strength. A propeller is a complex geometry which requires high end modeling software. The solid model of propeller is developed in CATIA V5 R9. Static, Eigen and frequency responses analysis of both aluminum and composite propeller are carried out in ANSYS 2. Inter laminar shear stresses are calculated for composite propeller by varying the number of layers. The stresses obtained are well within the safe limits of elastic property of the materials. Keywords: Ship Propeller, CFD, Static and Dynamic analysis using FEA package. Introduction The propeller is that component of the ship which converts the engine power into the driving force of the ship. These days, conventional marine propellers remain the standard propulsion mechanism for surface ships and underwater vehicles. Propeller being an important component for propulsion, more emphasis is done on design of the propeller. It has to withstand to the high pressure acting over on it. Numerical analysis performed on propeller for improving cavitations inception of propeller. Initially /6 th model of the trinket propeller is considered for analysis and experimental methods to estimate the thrust coefficient, torque coefficient and open water efficiency. The simulation results are validated with the cavitations tunnel results. Pressures are taken from the validated CFD analysis of the trinket propeller to carry out the structural analysis on the Trinket propeller. The structural analysis is done for both metallic and the composite material propellers. In the composite propeller varieties of layup sequenced are taken for the analysis and unique layer is predicted as the optimized layup sequence based on the deformations observed in the propeller. Modeling and Analysis f Ship Propeller The solution procedure of this thesis work involves the following steps:. Modeling by using CATIA V5 R8 2. CFD Analysis 3. Analysis using ANSYS 2. Modeling By Using CATIA V5 R8 Modeling of the propeller is done by using CATIA V5 R8. In is necessary to carefully model the propeller blades which is main consideration. The CATIA model of the propeller is shown in figure. Fig-: Solid Model of Ship Propeller Analysis of the Propeller The analysis of ship propeller has been carried out by using ANSYS 2. general purpose FEM software. The following analysis were done on the blower. Static analysis 2. Modal analysis 3. Harmonic analysis. CFD analysis IJAEM SRC. All rights reserved.

2 V. D. Rajeswari.Swarna, G. Balakrishna Results CFD Analysis of Propeller both Al and Composite VELOCITY (m/s) PRESSURE (mpa) Input Data Fig-2: Meshed Propeller Model Fluid Operating velocities Water 3. to 6.28 m/s Material Properties The material used for the metallic propeller is Aluminum Density, ρ= 27 kg/m 3 Poisson Ratio, µ=.3 Young's Modulus, E= 7GPa The material used for the metallic propeller is CARBON-UD Material = Carbon-Ud, Young's Modulus, E x = 75gpa, E y =gpa, E z =gpa, Density, Ρ= 6 Kg/M 3, N xy =.6, N yz =.35,N zx =.6, Rigidity Modulus, G xy =5.2gpa,G yz = 3.8gpa,G zx =6gpa. Fig-: Pressure Rate of Propeller and Related Figure FEM Results by Using Ansys 2. Sl. No Comparison between Composite Propeller and Aluminum Propeller Interms of Stress VELOCITY (M/S) STRESS (COMP) MM STRESS(AL) MM Fig-3: CFD Analysis of Propeller ISSN , Vol. 2, No. 5, September 23, pp. 5

3 Dynamic Analysis of Composite Propeller of Ship Using FEA Sl. No Comparison between Composite Propeller and Aluminuim Propeller Interms of Deformation Velocity (M/S) Deformation (Comp) Deformation (Al) Natural Frequencies of Propeller Mode Freqeuncy(Hz) Frequency(Hz) Shape Composite Aluminium Fig-5: Static and Dynamic Analysis of Aluminium Propeller ISSN , Vol. 2, No. 5, September 23, pp. 5

4 V. D. Rajeswari.Swarna, G. Balakrishna ELEMENTS AUG 23 2:9:3 LAYER STACKING ELEM = 66 SECT = LAYERS : Layer# Material# TOTAL = 26 Theta SHOWN : 2 FROM TO AUG 23 2:2:9 9 Fig-6: Composite Propeller Lay Up Sequence Fig-7: Static Analysis of Composite Propeller UZ_ AUG 2 23 ::8 UX_3 AUG 2 23 ::52 UY_2 AUG 2 23 :39:52 (x**-3) (x**-2) (x**-3) Fig-8: Dynamic Response of Propeller Fig-9: Stress and Deformation Comparison of Aluminum and Composite ISSN , Vol. 2, No. 5, September 23, pp. 5

5 Dynamic Analysis of Composite Propeller of Ship Using FEA Conclusion In this present work aluminum and carbon epoxy fiber propeller blade are modeled in CATIA V5 R8 and are analysis are preformed in ANSYS 2.. Pressures are taken from the validated CFD analysis of the trinket propeller to carry out the structural analysis on the Trinket propeller. In this project work structural, model and harmonic analysis are performed on composites materials and compared with aluminum materials. It is observed that if velocity increases pressure on propeller also increases. At all velocities, composite material is having % less deformation compared with aluminum. For the deformation the composite material are having less deformation compared with aluminum. Model analysis is performed to find out the natural frequencies of propeller and Harmonic analysis is used to find out where the max deformation takes place at which frequencies for aluminum and composite materials. Total results are compared in tables and plotted in graphs and tables. From all the above results composite material is having less deformation, less stresses and are in allowable limits. Future Scope of the Work. Total design can be done using theoretical calculations of hydrofoil blades. 2. By using above design results we can fabricate the model. 3. Impact and creep analysis can be performed using FEA technique and hydrodynamic concept.. Using different types of composites materials we can run the analysis and compares for optimum model References []. Francesso Salvatore V.H and Accosta AJ 973 Viscous Effects in the Inception of Cavitation on Axisymmetric Bodies, ASME J. Fluids Eng., 9, Pp [2]. Arakeri, V. H., 975, Viscous Effects on the Position of Cavitation Separation From Smooth Bodies, J. Fluid Mech., 68, Pp [3]. Arakeri, V. H., Carroll, J. A., And Holl, J. W., 98, A Note on the Effect of Short and Long Laminar Separation Bubbles on Desinent Cavitation, ASME J. Fluids Eng., 3, Pp []. Bong Jun Chang.998, A Holographic Study Of The Influence of Boundary Layer And Surface Characteristics on Inception and Developed Cavitation on Axisymmetric Bodies, Proceedings Of 2th Symposium on Na- Val Hydrodynamics, Washington, DC, Pp. 3. [5]. Antonio Sanchez-Caja., 998, Boundary Layer and Cavitation Studies of NACA 6 2 and NACA 2 Hydrofoils, Proceedings Of 3th Symposium On Naval Hydrodynamics, Tokyo, Japan, Pp [6]. Billet, M. L., And Holl, J. W., 98, Scale Effects on Various Types of Limited Cavitation, ASME J. Fluids Eng., 3 (3), Pp.. [7]. Zhanke Liu And Yin L. Young 29 Utilization of Bend Twist Coupling For Performance Enhancement of Composite Marine Propellers, department of Civil And Environmental Engineering, Princeton University, Princeton, NJ 85, USA [8]. Karl Randle And Peter Bull, March 25, Predictions of The Thrust And Torque Performance For Two Propeller Blades Using Computational Fluid Dynamics International Conference On Marine CFD, [9]. JL.Reboud, 26 A Method to Predict Cavitation Inception Using Large-Eddy Simulation And Its Application to The Flow Past A Square Cylinder, Institute Of Fluid Mechanics, Technische Universität, Dresden, ASME, Vol.28, 26. []. Sandor Bernad, Numerical Analysis of the Cavitating Flows, Center of Advanced Research In Engineering Sciences, Romanian Academy, Timisoara Branch, Romania, 26. ISSN , Vol. 2, No. 5, September 23, pp. 5