Aerodynamic characteristics of a wrap-around fin rocket

Abstract

Purpose – The purpose of this paper is to investigate the aerodynamics characteristics (especially the side force/moment and rolling characteristics), to analyze the impacts generated by different parameters of wrap-around fins (WAFs) and to find the corresponding mechanism. Design/methodology/approach – The paper has adopted three different types of WAFs for the rocket configurations and the sub-regions divided technology to investigate the lateral and rolling characteristics of WAFs, including the fins with variations in span to chord ratio, thickness, leading-edge sweep, curvature radius, fin numbers, setting angles and rotated angles. Simulations have been performed at Mach numbers from 3 to 4 through an angle-of-attack range of about 0° to 10° and at model rolling angles of 45° to 90°. Findings – The paper shows that the WAF configurations can greatly improve the longitudinal stability and enhance the longitudinal aerodynamic characteristics for the whole rocket. The total drag of the whole rocket is mainly stemmed from the body, while the drag generated by the WAF account for only about 7.42 per cent. The extra side forces and rolling moments are due largely to the unequal pressure distributions on both sides of the fin (windward or leeward). Maintaining a certain negative setting angle (d) can effectively avoid the coning movement and improve the flight stability at high angles of attack. The size of the span and chord are two main factors in controlling the longitudinal characteristics. For the side force/moment and rolling characteristics, different geometric parameters of the WAFs have played different roles. Originality/value – The paper provides the qualitative and quantitative analysis for different WAFs configurations by investigating the curves of different parameters and contouring of static pressure distributions. Findings can provide some suggestions for the designers for avoiding some significant dynamic problems, such as Magnus instability and roll rate variations during flight.

Numerical investigation of aerodynamic effects of opposite wrap-around fins at supersonic speeds

“…This is further investigated in various literature. 8 10–12,14,15 . However, it is observed that, by positioning the fins in an opposite arrangement, identical pressure distributions develop on either sides of the fin, ending up with the elimination of the rolling moment, so that the objective of the present research (elimination of rolling moment) is achieved.…”

“…Further, Zhang et al. 14 showed the span length and chord size are two main factors for controlling the longitudinal features. Zhang et al.…”

“…They found from stability point of view the WAF is more advantageous as compared with grid fin configuration. Zhang et al 14 investigated the aerodynamic characteristics of WAFs and found the corresponding mechanism by analyzing the effects of different parameters of WAFs. They studied the effects of following factors on the aerodynamics features of fins: factors such as span-to-chord ratio, thickness, leading-edge sweep, curvature radius, fin numbers, setting angles, and rotated angles.…”

Parametric study of different fins for a rocket at supersonic flow

“…[14][15][16][17][18][19][20][21][22][23] Our previous studies only focus on the qualitative and quantitative analysis for different Wrap-around fins (N ¼ 4, 6 and 8) by drawing the orthogonal tables for different parameters. 24 The current research will mainly focus on the characteristics comparisons between the flat fins and WAFs. The parametric studies on the flat fins and WAFs configurations are conducted, including the span to chord ratio, curvature radius as well as setting angles.…”

Investigation of the aerodynamic parameters simulation method of a guided rocket

“…Compared with the above methods, CFD is the kind of simulation method by which we can intuitively get the distribution of the flow field, and for the reasons that the process is simple and the results reliable and accurate, it is widely used for aerodynamic parameter calculations of guided projectiles, resulting in it becoming a hot area of aerodynamic research. For example, the CFD simulation has been used for the aerodynamic characteristic study of the spin-stabilized artillery shell by Hamel and Gagnon, 1 Je et al, 2 Fu et al, 3 and Yin et al, 4 used for the aerodynamic characteristic study of the fin-stabilized rocket by Afzal et al, 5 Sahu,6 Zhimin et al, 7 Sahu et al, 8 Zhang et al, 9 and López et al, 10 and used for the aerodynamic characteristic study of the mortar projectile by Su et al, 11 Li et al, 12 and Chengen et al 13 Most of the CFD simulations that are used for aerodynamic characteristic studies on projectiles, are focused on the effect of geometry on the aerodynamic parameter. The contrastive analysis of the CFD simulation method is relatively less.…”