Finite Element Analysis of Inertia Dynamometer R. A. Gujar 1, S. V. Bhaskar 2 & N. U. Yewale 3 1,2&3 Department of Mechanical Engineering, 1&3 Pimpri Chinchwad College of Engineering, 2 Sanjivani Rural Education Society College of Engineering E-mail : ragujartpopune@gmail.com 1, santoshbhaskar12002@yahoo.co.in 2, na.624@rediffmail.com 3 Abstract The Dynamometer is a LOAD device. It applies a load to an engine so we can test the performance of the engine under a variety of circumstances. System operates where load (dyno) torque equals that of the Engine. By varying the engine throttle and load we can test any point under the engines max torque curve. We design and modify engines for improved fuel economy and emissions We need DATA to quantify the improvements in Fuel savings and Emissions reductions. This data will be used to help us tune in our design. The Dynamometer is operated at 1000 rpm to generate the necessary inertia. For different kind of conditions, there is need of having variable inertia. So the dynamometer is constructed with removable flywheel. I. INTRODUCTION The Dynamometer is a LOAD device. It applies a load to an engine so we can test the performance of the engine under a variety of circumstances. System operates where load (dyno) torque equals that of the Engine. By varying the engine throttle and load we can test any point under the engines max torque curve. We design and modify engines for improved fuel economy and emissions. We need DATA to quantify the improvements in Fuel savings and Emissions reductions. This data will be used to help us tune in our design. Table I : Material Properties for Shaft Physical Properties Values Ultimate Strength 410 Mpa (N/mm 2 ) Yield Strength 230 Mpa (N/mm 2 ) Young s Modulus (E) 2.1x10 5 N/mm 2 Poisson s Ratio (µ) 0.3 Density 7850 kg/ m 3 Table II : Chemical Properties for Shaft Grade Desig nation FE 410 W Qua lity Ladle Analysis, % Max C Mn S P Si (CE) Max A 0.23 1.5 0.045 0.045.40 0.42 Table III : Mechanical Properties of Shaft Grade Designation Quality S yt MPa σ t MPa % Elongation, A at Gauge Length, L O 5.65 S,Min Method of Deoxidation SemiKille d/ Killed Internal diam. Min. FE 410 W A 410 230-250 23 3t B. ANALYSIS OF SHAFT BY USING FEA The Dynamometer is operated at 1000 rpm to generate the necessary inertia. For different kind of conditions, there is need of having variable inertia. So the dynamometer is constructed with removable flywheel II. STATIC ANALYSIS A. ANALYSIS OF SHAFT Material Properties for shaft : Steel : FE 410 WA : IS 2062 Fig.1 : CAD Geometry of Shaft 55
C. STATIC ANALYSIS OF BUSH Fig. 2 : Deformation in Shaft FIG. 5 : CAD GEOMETRY OF BUSH Fig. 3 : Von-Mises Stresses in Shaft Fig.6 : Deformation in Bush Fig.4 : Max.Shear Stress in Shaft Fig.7 : Von-Mises Stresses in Bush 56
D. STRUCTURAL ANALYSIS OF PEDESTAL BEARING E. STRUCTURAL ANALYSIS OF BASE FRAME Fig. 8 : CAD Geometry of Pedestal Bearing Fig.11 : CAD Geometry of Base Frame Fig. 9 : Deformation in Pedestal Bearing Fig. 12 : Deformation in Base Frame Fig. 10 : Von-Mises Stresses in Pedestal Bearing Fig.13 : Von-Mises Stresses in Base Frame 57
III. MODAL ANALYSIS OF DYNAMOMETER Operating Frequency of Dynamometer Rotating Speed (N) = 1000 rpm. Angular Velocity (ω) = 2πN/60 = 2 x π x 1000/60 = 104.71 rad/s Operating Frequency = ω / 2π = 104.71 / 2π = 16.66 Hz Natural Frequency of Dynamometer The product is been solved in ANSYS to find the Natural Frequency upto first three natural modes. Fig.14 : Model Shape II C. Model Shape III Natural Frequency: 117.14 Hz Max. Amplitude: 1.09 mm CASE I Shaft & Fixed Flywheel A. Model Shape I Natural Frequency: 47.539 Hz Max. Amplitude: 1.1 mm Fig.14 : Model Shape III CASE II Shaft, Fixed Flywheel & Removable Flywheel. A. Model Shape I Natural Frequency: 36.007 Hz Max. Amplitude: 0.51 mm B. Model Shape II Fig.13 : Model Shape I Natural Frequency: 112.25 Hz Max. Amplitude: 1.09 mm Fig.15 : Model Shape I 58
B. Model Shape II Natural Frequency: 48.711 Hz Max. Amplitude: 1.077 mm C. Model Shape III Fig. 16 : Model Shape II Natural Frequency: 69.494 Hz Max. Amplitude: 0.5788 mm Fig.19 : Deformation in flywheel due to centrifugal stress CASE II Shaft, Fixed Flywheel & Removable Flywheel. Fig. 17 : Model Shape III D. DYNAMIC ANALYSIS OF DYNAMOMETER (High Speed Effect) Assumption 1. The Fixed, Removable Flywheel & Shaft is perfectly balanced. 2. This Analysis will consider the centrifugal forces developed due to high speed. CASE I Shaft & Fixed Flywheel Fig. 20 : Deformation in flywheel & Removable Flywheel due to centrifugal stress Fig.18 : Stress developed due to centrifugal stress Fig.21 : Deformation in flywheel & Removable Flywheel due to centrifugal stress 59
. IV. RESULTS XXXX V. CONCLUSION The result of Static Analysis for shaft, Pedestal Bearing & Base frame confirms the safety & overall rigidity of dynamometer assembly. The Modal Analysis confirms the safety of product to operate at 1000 rpm speed, as the operating frequency doesn t meet to natural frequency. The dynamic analysis confirms the strength validation of the product. The average induced stress is lower than the yield strength of material, the product is safe. VI. ACKNOWLEDGMENT I wish to express my sincere thanks to Prof.S.V.Bhaskar for their technical support and helpful attitude gave us high moral support. I am also thankful to Prof. A.G.Thakur (P.G.Coordinator & HOD of Mechanical Department) who had been a source of inspiration. Finally, I specially wish to thank my father & Mother, wife kirti and sweet daughter Sanskriti and all those who gave me valuable inputs directly or indirectly. VII. REFERENCES [1] Min-Soo Kim, Vibration Analysis of Tread Brake Block in the Brake Dynamometer for the High Speed Train International Journal of Systems Applications, Engineering & Development, 2011, Volume 5, Issue 1. [2] J. Naga Malleswara Rao, A. Chenna Kesava Reddy & P.V. Rama Rao, Design and fabrication of new type of dynamometer to measure radial component of cutting force and experimental investigation of optimum burnishing force in roller burnishing process Indian Journal of Science and Technology, 2010, Vol. 3 No.7, ISSN: 0974-6846. [3] Min-Soo Kim, Jeong-Guk Kim, Byeong-Choon Goo, & Nam-Po Kim, Frequency Analysis of the Vibration of Tread Brake Dynamometer for the High Speed Train Vehicle Dynamics & Propulsion System Research Department, Korea Railroad Research Institute, ISSN: 1792-4618, ISBN: 978-960-474-217-2. [4] Ryan Douglas Lake, Integration of a small Engine Dynamometer into an eddy Current 60
Controlled Chassis Dynamometer B.S; University of Cincinnati, 2004. [5] Brian J. Schwarz & Mark H. Richardson, Experimental Modal Analysis, Vibrant Technology, Inc.1999. [6] J Michael Robichaud, P.Eng, Reference Standards for Vibration Monitoring and Analysis. [7] S.Vijayaraja, S.Vijayaragavan, Finite Element Analysis of Critical Components of the 2.6L Gasoline Engine AVTEC Ltd. [8] V.B.Bhandari, Design of Machine Element; Tata McGraw-Hill Publication Co.Ltd. New Delhi,2004. 61