NUMERICAL ANALYSIS OF MISSILE WITH MODIFIED FOREBODY IN DRAG REDUCTION

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 9, September 2018, pp , Article ID: IJMET_09_09_106 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed NUMERICAL ANALYSIS OF MISSILE WITH MODIFIED FOREBODY IN DRAG REDUCTION Department of Aeronautical Engineering, Sathyabama Institute of Science and Technology, India ABSTRACT Modern missiles symbolize an example of extremely integrated subsystems which cooperate together to guide the missile to its target. This paper studies the method to improve the stability and improve the performance by achieving reduced drag. One of the methods is the hole is drilled in the forebody of the missile. Due to the opening, the free stream air passes through the hole due to the physical property of flow. The effect of air passing through the forebody is calibrated computationally with the aid of CATIA and ANSYS-CFX. To avoid the uncertainty the values of lift coefficient, drag coefficient and thrust and that are calculated under the condition of the angle of attack 4.5 in varying Mach number 1.5, 2, 2.5. Additionally, turbulence, kinetic energy, pressure contour and velocity are evaluated to find the lift production and the pressure distribution over the structure of missile configuration. Further, the location of Centre of gravity and Centre of the pressure of the missile is found. Key words: Missile, Forebody, Drag Reduction. Cite this Article:, Numerical Analysis of Missile with Modified Forebody in Drag Reduction, International Journal of Mechanical Engineering and Technology 9(8), 2018, pp INTRODUCTION The missile is a self- propelled system which is guided by subsystems. There are several systems which include targeting system, flight system, guided system, engine and warhead. Way days back the first missile is fabricated by Nazi Germany during World War II [1-2]. Basically, there is two types of missiles, ballistic and cruise missile. A ballistic missile is the very best operational technology compared to other types of missile. On the contrary, it is very difficult to control. The aeroelasticity phenomena symbolize the domain factors of aerospace designs. The new design of missile structure, in a normal cruise missile by drilling a small hole of diameter 5mm. The hole is drilled from the top to the Bottom throughout the body of the missile[3]. When it is launched the air passes through the holes, due to the property of the air the free stream act like a stable rope. In spite, the background of this principle was previously applied to the BURJ KHALIFA building. Due to the removal of editor@iaeme.com

2 material from the missile forebody, the stability of the missile will increase and weight will also be reduced. On the other hand, the material property is derived [4 11] kinds of literature. 2. SIMULATION CFD analysis was done in ANSYS 18.1 software [12-19]. Two missile structures had been tested, one is normal missile model fully solid structure and another one is new design based on our concept whole section missile. Grid generation is the important step in CFD analysis. Ansys-ICEM platform used as the meshing process. The mesh is prepared in two stages: 1. Ansys- ICEM utilized to generate the surface mesh with tetragonal elements. 2. Surface mesh GTM files are used as volume meshing [20-24]. The Simulation was performed in a circular domain of 2 X The free stream assumed along x-axis. Inlet boundary condition assumed to be opening where the velocity is given in Mach number and outlet boundary condition is taken as pressure domain. The model missile with and without hole engrossed in the domain. Further, the wall boundary condition is taken as a slip wall. The grid size of the model is 200 x 10 x 50 to 200 x 100 x 110 with the uppermost resolution x= RESULTS AND DISCUSSION The surface mesh is generated using Delaunay method. The Delaunay method is a default method which is used by several pioneers. On the other hand, the alternative surface mesh uses an Advancing Front (AF) method. The volume mesh is used by creating the Advancing Front and Inflation (AFI). Before meshing can be started, it is necessary to set up the control volume for the problem. A large control volume was taken to understand the flow physics as the flow analysis was performed for higher angle of attack. After the domain had been setup, meshing was carried out. The unstructured, tetra mesh with following statistics was generated. After completing mesh CFD is done for both missile designs in angle of attack 45. In this velocity, pressure, turbulence kinetic energy contour in both missile structures. Basically missile stability must be center of pressure (CP) behind the centre of gravity (CG). So centre of gravity of a rocket is the point at which all the weight of the rocket seems to concentrate. That is, there is as much weight distributed ahead of the rocket centre gravity as there is behind it. Figure 1 Pressure contour for both models editor@iaeme.com

3 Numerical Analysis of Missile with Modified Forebody in Drag Reduction Figure 2 Velocity contour of both missiles Figure 3 Streamline contour of missiles The modified missile design and the existing missile design were tested in ANSYS software. Some tests like velocity contour, pressure contour, turbulence kinetic energy were done in all the three models. These tests were done in order to prove that the modified missile can be more stable and can attain extra mach speed. Figure 1-3 represents the contour plot of the CFD. Figure 1 shows the pressure variation for the mach 2 and figure 2 shows the velocity. The pressure distribution around the missile varies with attitude. At lower angles of attack, it seen from the profile that the stagnation point is obtained on the lower surface. So a stable angle 45 o degree was taken. This same angle was used in all tests of all three missiles. Mach speed was changer from 1.5 to 2 and then 2.5. This three mach speeds were used In order to get more results so that the comparison of the results can be done. The result got from all the two models were compared to get the best result from the exact model. So that the values were compared to the values of existing model of missile. The stability has to be increased that is the main scope of the project, to gain this the missile body has to be modified. When there is no friction, there reduces the drag. This leads to high speed there will be no resistance of speed. So that extra range also can be achieved. The table 1 and table 2 presents the coefficient of lift and drag to the Mach number, it is evident that Type A perform editor@iaeme.com

4 better than Type2. Table 3 shows the effect of thrust where Type B gives high power than Type A. Figure 4 and 5 represent the table in graphical representation. Table 1 C L values for various Mach number Mach number Type A Type B Figure 4 Plot for Mach number vs lift coefficient Table 2 C D values for various Mach number Mach number Type A Type B Figure 5 Plot for Mach number vs lift coefficient editor@iaeme.com

5 Numerical Analysis of Missile with Modified Forebody in Drag Reduction Table 3 Thrust force values for various Mach number Mach number Type A Type B From the table 1 to 3 and the figure 4 and 5, it is eventually proved that the missile with fins provides lesser stability compared with the missile without fins and with holes on the forebody. 4. CONCLUSIONS The analysis of flow characteristics over missile has been carried out successfully. From the classification of results it is found that the values of Cp, Cg and thrust with respect to Mach number is increasing the lift force and decreasing the drag force. Further it is found that higher the distance of Cg and Cp enhances the stability. The stability of the system is marginally affected due to the increased mach number owing to the thrust and lift force which is directly proportional to Mach number. The result obtained from the blend with hole missile shown a appreciable reduction in drag at Mach 2.5, the drag force obtained is N. Further, the conventional model minted N which is considerably higher than the blend missile. On the other hand, conical missile at Mach number 2, yields the value is Kgm/s 2 by comparing this value with the value of existing missile model, totally Kgm/s 2. The value of CG and CP are mm and mm respectively. By having presence the concept of Blend missile and conical missile with hole, the stability of the missile improved with reduced drag force. REFERENCES [1] Chen Bai, Luo Mingqiang,Wu zhe, Rapid structure design and automated adjustment of civil aircraft fuselage, Journal of Beijing University of Aeronautics and Astronautics,2014. [2] Hintapalli S, Elsayed M S A, Sedaghati R, The development of a preliminary structural design optimization method of an aircraft wing-boxskin-stringer panels, Aerospace Science & Technology, [3] Li Jixinga, Ning Taoa, Xi Pinga, Wang Tian Rapid structure design and automated adjustment of missile body on Science Direct, [4] Manigandan S. Computational Investigation of High Velocity Ballistic Impact Test on Kevlar 149. InApplied Mechanics and Materials 2015 (Vol. 766, pp ). Trans Tech Publications. [5] Manigandan S. Determination of Fracture Behavior under Biaxial Loading of Kevlar 149. InApplied Mechanics and Materials 2015 (Vol. 766, pp ). Trans Tech Publications. [6] Gunasekar P, Manigandan S, Anderson D, Devipriya J. Evaluation of Fe-Epoxy metal nanocompopsite in glass fiber and Kevlar. International Journal of Ambient Energy. 2017: editor@iaeme.com

6 [7] Devipriya J, Manigandan S, Gunasekar P, Nithya S. Experimental Evaluation of Metal Nanocompopsite Al-Epoxy in Kevlar. Journal of Chemical and Pharmaceutical Sciences ISSN. 2016; 974:2115. [8] Nithya S, Manigandan S, Gunasekar P, Devipriya J, Saravanan WS. Investigation of Stacking Sequence on Glass and Kevlar Fiber. Journal of Chemical and Pharmaceutical Sciences ISSN.; 974:2115. [9] Nithya S, Manigandan S, Devipriya J, Gunasekar P. Finite Element Analysis of Droplet Impact on Kevlar Flat Plate. Journal of Chemical and Pharmaceutical Sciences ISSN.; 974:2115. [10] Gunasekar P, Manigandan S. Computational analysis of frp composite under different temperature gradient. InIOP Conference Series: Materials Science and Engineering 2017 May (Vol. 197, No. 1, p ). IOP Publishing. [11] Manigandan S, Gunasekar P, Nithya S, Revanth GD, Anudeep AV. Experimental analysis of graphene nanocomposite on Kevlar. InIOP Conference Series: Materials Science and Engineering 2017 Aug (Vol. 225, No. 1, p ). IOP Publishing. [12] Manigandan S, Vijayaraja K. Acoustic and mixing characteristic of CD nozzle with inverted triangular tabs. International Journal of Ambient Energy Jul 20:1-5. [13] Manigandan S, Vijayaraja K. Flow field and acoustic characteristics of elliptical throat CD nozzle. International Journal of Ambient Energy Aug 17:1-6. [14] Manigandan S, Gunasekar P, Devipriya J, Nithya S. Determination of heat flux on dual bell nozzle by Monte carlo method. Journal of chemical and pharmaceuticals sciences [15] Gunasekar P, Manigandan S, Devipriya J, Saravanan WS. Investigation of Dual Mode RJ Nozzle by Discrete transfer method. Journal of Chemical and Pharmaceutical Sciences, ISSN. 2016;974:2115. [16] Manigandan S, Vijayaraja K, Gunasekar P, Nithya S, Devipriya J, Ilangovan N. Mixing characteristics of elliptical throat sonic jets from orifice and nozzle. International Journal of Ambient Energy Nov 16:1-3. [17] Manigandan S, Vijayaraja K. Energy decay characteristics of a non-circular supersonic jet. International Journal of Ambient Energy Feb 22:1-4. [18] Manigandan S, Vijayaraja K, Revanth GD, Anudeep AV. Mixing and Entrainment Characteristics of Jet Control with Crosswire. InAdvances in Machine Learning and Data Science 2018 (pp ). Springer, Singapore. [19] Manigandan S, Vijayaraja K. Flow Mixing and Screech Characteristics of Elliptical Supersonic Jet. International Journal of Turbo & Jet-Engines DOI: /tjj [20] Manigandan S, Gunasekar P, Devipriya J, Anderson A, Nithya S. Energy-saving potential by changing window position and size in an isolated building. International Journal of Ambient Energy May 10: editor@iaeme.com

7 Numerical Analysis of Missile with Modified Forebody in Drag Reduction [21] Devipriya J, Manigandan S, Nithya S, Gunasekar P. Computational Investigation of Flow over Rough Flat Plate. Journal of Chemical and Pharmaceutical Sciences, ISSN. 2017;974:2115. [22] Manigandan S, Gunasekar P, Devipriya J, Saravanan WS. Reduction of greenhouse gases by the effect of window position and its size in isolated building. Journal of chemical and pharmaceuticals sciences [23] Manigandan S, Gunasekar P, Sruthisree N, Aich K, Sathya K, Selvan A, Nithya S. Visualization of vortex flow field around a flat plate with noncircular hole. InIOP Conference Series: Materials Science and Engineering 2018 Feb (Vol. 310, No. 1, p ). IOP Publishing. [24] Manigandan S, Kumar KG, Gunasekar P, Nithya S. Experiment Evaluation of Skin Friction Drag by Surface Tailoring. InIOP Conference Series: Materials Science and Engineering 2017 Aug (Vol. 225, No. 1, p ). IOP Publishing editor@iaeme.com