iCLEAN – Loitering Attack UCAV 1 ABSTRACT The following report presents the entire work process that had been done during the year of 2011-2012, as part of a student project of the Aerospace faculty at the Technion Institute of Technology. The "iCLEAN" project. "iCLEAN" is a suicide Unmanned Combat Air Vehicle (UCAV) with loitering and reconnaissance capabilities, designed to perform missions beyond line-of-sight in a range of 400 [NM] and for a long period of time, suggesting a long endurance of just about 5[hr]. Carrying a 20+ warhead and equipped with an EO/IR (Electro-Optical and Infra-Red) sensor, the "iCLEAN" provides an advantage to the forces on the ground and constitute a big threat on the enemy during combat. During the work process a UCAV configuration survey was conducted, two configurations were chosen for the preliminary design. One of those configurations had been chosen due to several comparisons and requirements arose during the process. A detailed design and a wind tunnel model test were conducted on the chosen configuration in order to ensure that the theoretical calculations and design are valid. 2 TABLE OF CONTENTS Abstract ......................................................................................................................... 2 Table of Contents .......................................................................................................... 3 1. Introduction ............................................................................................................ 13 2. Customer Specifications ......................................................................................... 14 3. Mission Profile ........................................................................................................ 15 4. Market Survey ......................................................................................................... 16 4.1. Market Survey – Configurations ............................................................................... 16 4.1.1. HARPY ................................................................................................................. 17 4.1.2. HAROP ................................................................................................................ 19 4.1.3. HARPY, HAROP and Required UAV Comparison ............................................. 21 4.2. Market Survey - Sub Systems .................................................................................... 22 4.2.1. Sensors ............................................................................................................... 22 4.2.2. Engines ............................................................................................................... 24 4.2.3. Launcher Technology Selection ........................................................................ 25 5. Preliminary Design ................................................................................................. 27 5.1. Initial Sizing ................................................................................................................ 27 5.1.1. Initial Weight Estimation .................................................................................. 27 5.1.2. Initial Wing Geometry Evaluation .................................................................... 30 5.1.3. Power-to-Weight Ratio and Wing Loading ...................................................... 42 5.1.4. Revised Weight Estimation ............................................................................... 46 5.1.5. Initial and Revised Evaluation Comparison..................................................... 50 5.1.6. Revised Geometry Evaluation ........................................................................... 51 5.2. Configurations Review .............................................................................................. 52 5.2.1. Configuration A .................................................................................................. 53 5.2.2. Configuration B ............................................................................................ 57 5.2.3. Configurations Comparison .............................................................................. 62 5.2.4. Final Combined Configuration .......................................................................... 66 5.3. Radar Cross Section- RCS .......................................................................................... 67 5.3.1. RCS Calculated ................................................................................................... 67 6. PDR Remarks .......................................................................................................... 69 7. Detailed Design ....................................................................................................... 70 7.1. Propeller Selection ..................................................................................................... 70 7.2. Airfoil Selection .......................................................................................................... 76 7.3. Rocket Booster ........................................................................................................... 79 7.3.1. Booster Design and Sizing ................................................................................. 79 3 7.3.2. Moment vs. Time For Different Booster Angles .............................................. 79 7.4. Plane Geometry Improvements ................................................................................ 82 7.5. Aerodynamic .............................................................................................................. 84 7.5.1. Lift Coefficient .................................................................................................... 84 7.5.2. Drag Coefficient .................................................................................................. 91 7.6. Performance Calculations ......................................................................................... 92 7.6.1. Thrust Calculations ............................................................................................ 92 7.6.2. Velocity Calculations ......................................................................................... 93 7.6.3. Climb & Turn Calculations ................................................................................ 94 7.6.4. Range and Endurance ........................................................................................ 96 8. Wing Detailed Design.............................................................................................. 98 8.1. Wing Structure - Introduction .................................................................................. 98 8.2. Wing Structure – Design .......................................................................................... 101 8.3. Calculations of The Thickness of The Web ............................................................ 104 8.4. Calculation of The Hinges Area ............................................................................... 105 8.5. Calculation of The Skin Thickness .......................................................................... 107 8.6. Wing Root Joints ...................................................................................................... 110 8.7. Pivot Modeling ......................................................................................................... 115 8.8. Pivot Stress Calculatiobs and Analysis ................................................................... 117 8.8.1. Stress Calculations ........................................................................................... 117 8.8.2. Analysis ............................................................................................................. 119 9. Wing's Folding Mechanism ................................................................................... 122 9.1. Description of The Displayed Solution ................................................................... 123 9.2. Calculations .............................................................................................................. 124 9.3. Mechanism Components ......................................................................................... 126 9.3.1. The Calculation of Bearing and Hinge Diameters ......................................... 126 9.3.2. Choosing of The Main Spring ................................................................. 128 9.3.3. Connecting Rods Between The Spring and The Wings ................................. 131 9.3.4. Movement Limiters Design ............................................................................. 131 10. Final Configuration ............................................................................................. 133 10.1. Internal Layout of The Components .................................................................... 135 10.2. Weights Table ........................................................................................................ 136 10.3. Aerodynamic Calculations .................................................................................... 137 10.3.1. Center of Gravity ............................................................................................ 137 10.3.2. Aerodynamic Center ...................................................................................... 139 10.3.3.