SOLAR PANEL DEPLOYMENT:Deployment of solar panels has considerable influence on dynamic and attitude control of satellite and may make disturbances. To prevent and minimize of these disturbances in attitude control of a satellite, it is necessary to design a deployment mechanism for the solar panels which has appropriate performance and ability to control the disturbances and also can be constructed.

The mechanism should make constant angular velocity, and it is preferred to be simple and to have small weight and high performance. Because of these things, deployment mechanism involves a torsion spring for deployment and tape spring for locking mechanism. Locking of solar panels at intended position is necessary for satellite to perform its mission successfully. The deployment mechanism should have high precision and reliability. Consequently, the analysis on the dynamic behavior of the deployment mechanism must be done at initial design stage.

MAJOR TASKS OF THE PROJECT:•Designing of Cold Gas Thruster

• Performance of CD Nozzle

• Flow & Stress Analysis of Thruster(Fluent)

• Designing of Pressure Vessel

• Issues in Solar Panel Deployment

• Designing of Double Torsion Spring

• Designing & Analysis of Tape Spring(Abaqus)

DESIGN AND DEVELOPMENT OF COLD GAS PROPULSION SYSTEM AND SOLAR PANEL DEPLOYMENTMECHANISM FOR A LEO (LOW EARTH ORBIT) SATELLITE

Hassaan Munawar , Muhammad Tayyab , Abdullah Khalil , Richardson.P.Joseph.Advisor: MR. SHAKEEL AHMED

Department of Industrial & Manufacturing EngineeringNED University of Engineering & Technology

AcknowledgementsContinued collaboration of NED University of Engineering and Technology and SUPARCO is highly acknowledged.

COLD GAS THRUSTER DESIGNINGAssumptions for Flow conditions

• Isentropic Flow• One-Dimensional Flow• Steady Flow

FLOW ANALYSIS IN NOZZLE USING FLUENT

PRESSURE VESSEL DESIGN•The spherical pressure vessel was considered

•Material Selection:

TORSION SPRING DESIGN AND ANALYSIS

Solar Panels

Solar panel being deployed in a Satellite

Flow behavior in CD nozzle

• Element type: SOLID92 3-D 10-Node Tetrahedral Structural Solid

• Aluminum was considered with a nozzle thickness value of 1 mm.

• Max stress = 103 MPa

• Yield point = 255 MPa (Aluminum 6061-T6 Alloy )

Shear Stress

Ultimate Tensile Strength = 993 MPa Modulus of Elasticity = 114 GPa Tensile Yield Strength = 924 MPa Shear Strength = 760 MPa

Flange for TIG welding

Hole for boss insertion

Titanium alloys undergo about 20% deformation in spin forming. Hence the blank should be 20 % less in surface area than the surface in the area of hemisphere.

R = 435 mm

t = 6 mm

M2

Bracket for attachment with satellite body

Basic Spring Calculations1.Wire diameter (d) = 0.2938 in.2.Tentative mean diameter at maximum 3.working position. DT = 10 (d) = 10 (0.2938) = 2.938 = 3 in

TAPE SPRING-DESIGN AND ANALYSISBoundary conditions; Element Type is S4R which is a 4 node doubly curved general purpose shell element Structured meshing method was used .

The isometric view of designed tape spring

Meshed model of a Tape Spring

B- SolutionSince the analysis is geometrically nonlinear, so, the function NLGEOM was

used.The solution of this nonlinear problem is found by breaking the simulation

into increments The minimum and maximum increment size defined is 0.001 and 0.01 respectively.

For the convergence of solution. Therefore automatic stabilization option is used with a dissipated energy fraction of 0.0002 and adaptive stabilization with maximum ratio of stabilization to strain energy equal to 0.05.

Fully deformed shape(Abaqus)