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Dhiren Modi. Active Control of Flow Progression in the Vacuum Infusion Process Using Real-Time Flow Simulations. SAMPE-UK & Ireland Chapter Student Competition. Date: 22/11/05. Introduction Objectives Analytical study of pressure profile in the VI process Proposed Control Strategy
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Dhiren Modi Active Control of Flow Progression in the Vacuum Infusion Process Using Real-Time Flow Simulations SAMPE-UK & Ireland Chapter Student Competition Date: 22/11/05
Introduction Objectives Analytical study of pressure profile in the VI process Proposed Control Strategy Experimental Results Conclusions Outline
Without Flow Enhancement Media With Flow Enhancement Media Vacuum Infusion (VI) Process
Issues in VI Process • Process Optimisation • Fill-time Minimisation • Void Reduction • Resin Wastage Minimisation • Complex Nature of Flow • Preform Compaction • Flexible Mould • Flow Induced Changes in Compaction • Multi-scale (Fiber vs. Tow) Flow • Reinforcement Heterogeneity Control of Flow Important but Difficult !
To Investigate the Pressure Profile in the VI process To Develop and Validate a “FULLY AUTOMATED FLOW CONTROL SYSTEM” for VI process Objectives
Analytical Solution Rectilinear Flow From Continuity Equation, Using Darcy’s Law Iterative Solution Procedure Vfo and B - Fitting Coefficients
Rectilinear Pressure Profile Fitting Coefficients from Saturated Expansion
Analytical Solution Radial Flow From Continuity Equation, Using Darcy’s Law Iterative Solution Procedure Vfo and B - Fitting Coefficients
Radial Pressure Profile Fitting Coefficients from Saturated Expansion
To Investigate the Pressure Profile in the VI process To Develop and Validate a “FULLY AUTOMATED FLOW CONTROL SYSTEM” for VI process Objectives
Open all injection ports Acquire image at every fixed time interval Control injection ports Optimum port Configuration? Analyze the image No Pre-defined no. of nodes are filled? Yes No All the nodes are filled? Close all injection ports Yes Stop Proposed Control Strategy Start Perform Numerical Simulations
Flow sensing system Cost-effective Less intrusive Linkable with controls hardware Daisy-Chaining Prerequisite • Simple and Cheap Solution • Webcams ! • FireWireTM Camera (£100 Each)! • Daisy-chaining Capability • Better Performance
Image Analysis Filter Design Data Processing Mesh Correlation Gate Scheme Selection Hardware Implementation Challenges
Image Pixels Mesh Nodes Mesh Correlation
Gate Scheme Selection An Injection Scheme with Dmin is Selected!
Permeability Distribution Last Filled Region (With Controls) Filling Pattern (W/out Controls) Virtual Experiments Mean:- 1E-08 m2, S/D:- 2.29E-09 m2
Uncontrolled Experiments(Random Mat) Vent Unfilled Region, When Resin Reaches at the Vent (Centre of the mould)
Controlled Experiments (Random Mat) Vent Unfilled Region, When Resin Reaches at the Vent (Centre of the mould)
Uncontrolled Experiments Controlled Experiments Control Efficiency (Random Mat)
Uncontrolled Experiments(Modified Lay-up) Vent Unfilled Region, When Resin Reaches at the Vent (Centre of the mould)
C C O C C O C O O O C C O C C C O O C O C O C O C C O O O O O O O O O O O C - Open the injection gate - Close the injection gate Controlled Experiments(Modified Lay-up)
Controlled Experiments(Modified Lay-up) Vent Unfilled Region, When Resin Reaches at the Vent (Centre of the mould)
Uncontrolled Experiments Controlled Experiments Control Efficiency (Modified Lay-up)
The pressure gradient in the saturated region of the mould can be similar for the VI and the RTM processes for many of the low-compliant reinforcements. A new control scheme was developed and demonstrated. The control system is able to identify the macroscopic flow deviations and take appropriate control action for efficient infusion. Conclusions
Acknowledgements • Supervisors • Dr. Michael Johnson • Prof. Andrew Long • Prof. Christopher Rudd
Dhiren Modi Active Control of Flow Progression in the Vacuum Infusion Process Using Real-Time Flow Simulations SAMPE-UK & Ireland Chapter Student Competition Date: 22/11/05