Patent Publication Number: US-2023160671-A1

Title: Airflow Plate Fins

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon, and incorporates by reference, prior pending U.S. Provisional Patent application Ser. No. 63/281,154, filed Nov. 19, 2021, and entitled Airflow Plate Fins, by inventor Fernando Gomez de Avila Diaz, an American Citizen, and priority based on said provisional filing is hereby claimed. 
    
    
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates generally to airflow fin designs for stabilizing and controlling rockets in flight. More particularly, the present invention relates to aircraft and rockets plate fins that are designed for decelerating flight when deployed. Known prior art is classified in USPC 244, Subclasses 3.1, 3.24, and 3.28. 
     II. Description of the Prior Art 
     In the past, a variety of aerodynamic fins have been employed for stabilizing and controlling aerodynamic vehicles such as rockets during flight. Conventional grid fins generate lift or control forces when rotated out of alignment, or when set at incidence with the air flow. Traditionally, there have been employed two basic types of folding fin systems. In a first type, airfoil-shaped grid fins are stowed so that they snap open in a direction parallel to the flight path. In a second type, side-deploying grid fins wrap around the circumference of the body of the rocket to minimize undeployed volume required for storage during transportation. 
     A lattice or grid fin system consists of several essentially rectangular “paddles” filled with a grid of approximately triangular, square, and diamond-shaped cells formed by a cross-hatching of thin metal. The fins are fixed to the rocket body at the root end in a manner that allows them to be folded flat against the body of the rocket in storage. Upon launch, the fins are deployed with their broad lattice face perpendicular to the rocket body axis and are attached to internal mechanisms that allow the fin to be moved for directional control of the payload. Deployment is reliable because air loads on the fin are usually in the direction of desired motion, although springs or other devices may be used to assure or hasten deployment. 
     With all their advantages, grid fins comprise complex structures that can be difficult and costly to manufacture. They occupy storage space, and they are an important source of drag when they are wrapped or folded around the aerodynamic vehicle. 
     Therefore, there is a need for a new type of fin that has different characteristics and capabilities for use to control rockets or particularly reusable rockets. 
     Conventional grid fins are disclosed in American Institute of Aeronautics and Astronautics paper AIAA 93-0035, entitled “Grid Fins—A New Concept for Missile Stability and Control,” by W. D. Washington, U.S. Army Missile Command, Redstone Arsenal, Alabama. This paper was presented at the 31st Aerospace Sciences Meeting &amp; Exhibit. Jan. 11-14, 1993. The disadvantage of the grid fins presented in this paper is that the arrangement of the internal grid precludes parallelogram folding and the corresponding use of flexible material for grid and box sides. Thus, this conventional grid fin arrangement is precluded from folding around the body of the missile and provide for a compressed storage configuration. 
     The US has undertaken an extensive evaluation of the lattice or grid fin concept. The first US patent on grid fin technology, U.S. Pat. No. 5,048,773, issued in 1991 and is held by the U.S. Government. This reference discloses a curved grid fin that is constructed of strips of thin gauge metal such as teal honeycomb, which are secured together in a grid pattern with the honeycomb structure enclosed around the periphery of an aerodynamic vehicle. The rocket fin designed provides surface that can control, guide or decelerate a rocket. 
     A Russian reference for use of these devices in supersonic powered rockets such as the AA-12. Fulghum, David, “Lattice Fin Design, Key to Small Bombs,” Aviation Week &amp; Space Technology. 
     Numerous aerodynamic and systems studies, most notably by Mark Miller and David Washington, have been conducted over the past. Miller, M. and Washington, D., “An Experimental Investigation of Grid Fin Design”; Miller, M. and Washington, D. “An Experimental Investigation of Grid Fin Drag Reduction Techniques”; and Miller, M. and Washington, D., “Grid Fins-A New Concept for Missile Stability and Control.” 
     These studies have shown that lattice fins are aerodynamically effective control surfaces that have slightly higher drag than conventional airfoil fins. If increasing priority is given to compact storage, lattice fins have an advantage over conventional systems. They offer interesting secondary advantages as well. They can operate at high angles of attack without flow separation because the multiple channels of the lattice act as guides controlling the flow. Because of their small size and small center-of-pressure travel with large changes of angle of attack, actuator size and power for controllers can be greatly reduced, leaving more space in an air-born system for fuel and other useful payload. Perhaps more importantly for internal carriage, lattice fins allow an air-born payload to maintain similar capability in a smaller package compared to a conventionally finned payload. 
     Prior art related to the instant invention includes the following U. S. patents: 
     
       
         
           
               
               
             
               
                   
               
               
                 Patent No. 
                 Title: 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                 5,048,773 
                 Curved grid fin. 
               
               
                 7,829,829 
                 Grid fin control system for a fluid-born object. 
               
               
                 10,852,111 
                 Pressure relief fins for improved roll control 
               
               
                   
                 of precision projectiles. 
               
               
                 7,800,032 
                 Detachable aerodynamic missile stabilizing 
               
               
                   
                 system. 
               
               
                 7,429,017 
                 Ejectable aerodynamic stability and control. 
               
               
                 7,243,879 
                 Lattice fin for missiles or other fluid-born 
               
               
                   
                 bodies and method for producing same. 
               
               
                 7,114,685 
                 Wing for an aircraft or spacecraft. 
               
               
                 6,928,715 
                 Method for producing lattice for missiles or 
               
               
                   
                 other fluid-born bodies. 
               
               
                 6,502,787 
                 Convertible vertical take-off and landing 
               
               
                   
                 miniature aerial vehicle. 
               
               
                 6,460,807 
                 Missile components made of fiber-reinforced 
               
               
                   
                 ceramics. 
               
               
                 5,642,867 
                 Aerodynamic lifting and control surface and 
               
               
                   
                 control system using same. 
               
               
                   
               
            
           
         
       
     
     SUMMARY OF THE INVENTION 
     Provided are curved airflow plate fins adapted to be mounted and deployed upon rockets to guide the trajectory under the action of given forces. 
     The fins are preferably constructed of relatively high gauge metal such as steel, and they are located on the rocket in a triangular arrangement. When deployed the fins contribute to deceleration and breaking. The airflow plates can be extended outwardly from their housing, and then rotated transversely with respect to the longitudinal axis of the rocket. The airflow plate fins have geometric openings to improve their performance against incoming forces. Under supersonic speed their curved shape increases the capabilities of friction between the forces acting against them. 
     Thus, a basic object is to provide control fins for a rocket that can increase drag and decelerate the rocket when desired. 
     A related object is to provide perforation patterns within such fins that help decelerate the rocket. 
     A further object of this invention is to provide a curved surface on the airflow plate fin to accentuate the capabilities that can be used as a drag brake and control on a rocket and can be coupled to an actuator disposed within the vehicle and connected to the aerodynamic lifting and control surface for rotating it. 
     Another important object is to provide specific geometric openings in an airflow plate fin that are configured to improve performance. 
     A related object is to provide a rocket fin of the character described that, when activated and aligned perpendicularly to the air flow direction, offers more dynamic resistance to the opposite wind forces, thereby improving aerodynamic vehicle control, vehicle deceleration, and maneuverability, during descent towards a specific target. 
     These and other objects and advantages of the present invention, along with features of novelty appurtenant thereto, will appear or become apparent in the course of the following descriptive sections. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a top plan view of the preferred airflow plate fin, showing the overall shape; 
         FIG.  2    is a side elevational view of my airflow plate fin; 
         FIG.  3    is a combined diagrammatic and top plan view of the airflow plate fin fully deployed; 
         FIG.  4    is combined diagrammatic and top plan view of the plate fin retracted position; 
         FIG.  5    is a combined perspective and diagrammatic view of a rocket with the airflow plate fins fully deployed; 
         FIG.  6    is a combined perspective and diagrammatic view of a rocket with the airflow plate fins attached to its sides. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With initial reference now directed to  FIGS.  1  and  2   , my new control fin has been generally designated by the reference numeral ( 1 ). It comprises a shaped actuator shaft adaptor ( 2 ) adapted to be connected to the fuselage of the booster rocket via a typical movable joint or hinge mechanism (not shown) activated by the flight control system.  FIG.  1    also shows the numerous specific geometric openings ( 3 ) of different shapes and sizes that can be dimensionally adjusted in the manufacturing process depending on the required necessities. Those geometric openings allow air flow through them. At the same time the surface of the curved plate that is not hollow will present a resistance to the forces acting in the opposite way, increasing drag, slowing down the aerodynamic vehicle and facilitating its control before the vehicle reaches its desired objective. 
     Referencing  FIG.  2   , which is a side view showing my curved airflow plate fin ( 4 ) and how the opposite forces, represented by the reference numeral ( 5 ), collide on the plate when deployed fully on the side of the aerodynamic vehicle traveling at great speed. 
       FIG.  3    shows the top of an airflow plate fin ( 6 ) fully deployed and attached to the side of the aerodynamic vehicle ( 7 ). 
       FIG.  4    is top plan view of the airflow plate fin ( 8 ) in a retracted position and parallel to the side of the aerodynamic vehicle ( 9 ) to diminish drag and improve the flight capabilities of the booster rocket. 
       FIG.  5    is a perspective view of a rocket with two airflow plate fins fully deployed ( 10 ) and one in the retracted position ( 15 ), representing a three-fin triangular arrangement articulated (rotated) on their perpendicular axis by the control flight system ( 11 ) located in the interior of the booster rocket ( 12 ) with the objective of providing stability and control with small hinge movements. The two curved airflow plate fins ( 10 ) are arranged with their plate openings to the direction of rocket or missile motion ( 13 ) and against the incoming airflow forces ( 14 ). 
       FIG.  6    is a side view of the curved airflow plate fins ( 16 ) attached to the sides of the booster rocket ( 12 ) and completely deployed and re-orientated to the external surface of the aerodynamic vehicle, exemplifying their rotation commanded by the control flight system ( 11 ) with sufficient strength to sustain the required aerodynamic and inertial loads. Thus, there has been disclosed an aerodynamic lifting and control surface for use with aerodynamic vehicles such as rockets, and the like, that may be stowed in the body of the vehicle to provide for compact storage of rocket ( 16 ) and completely deployed and re-orientated to the external surface of the aerodynamic vehicle, exemplifying their rotation commanded by the control flight system ( 17 ) with sufficient strength to sustain the required aerodynamic and inertial loads. 
     Thus, there has been disclosed an aerodynamic lifting and control surface for use with aerodynamic vehicles such as rockets, and the like, that may be stowed in the body of the vehicle to provide for compact storage. It is to be understood that the described embodiments are merely illustrative of some of the many specific embodiments which represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention. The intended application for use to control rockets, or particularly, reusable booster rockets, determines the specific choice of a light weight and storability of the airflow plate fin embodiment and configuration to substitute and improve the capabilities of conventional grid fins. The airflow plate fin must be sufficiently robust to withstand the loading of forces against its surface requiring effective performance at supersonic, subsonic, or transonic speeds. In some applications, minimizing drag and the ability to function at high temperatures is important, whereas in other applications those capabilities are of less concern. 
     The airflow plate fin produces aerodynamic lifting for stability and controls the direction of the rocket when is deployed from a parallel position to the body to which is attached with hinges and aligned perpendicular to the air flow direction. 
     The geometric orifices located on the circular curved airflow plates are configured to optimize the flight performance characteristics of the aeronautic vehicle shaped in the form of one central circle, five triangles with their bases aiming towards the central circle, and five semicircular openings close to the outer perimeter of the airflow plate. The sum of the areas of the openings is approximately between three quarters and one half of the total surface of the individual plate, and those can be enlarged or reduced in the manufacturing process to achieve aerodynamic stability and control in order to satisfy the needs of a variety of deployed aeronautic vehicles, consequentially increasing or decreasing the resistance that the plate&#39;s surface will encounter when moving at high flight speeds. The total surface area of the circular curved plate will depend on the size and the characteristics of the aeronautic vehicle and its specific desired performance under given circumstances. From the foregoing, it will be seen that this invention is one well adapted to obtain all the ends and objects herein set forth, together with other advantages which are inherent to the structure. 
     It will be understood that certain features and sub-combinations are of utility and can be employed without reference to other features and sub-combinations. 
     As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.