Engineering Projects | Sammy Hallaj Portfolio

Mechatronics & Research Current Project

Acoustic Emissions Imaging System

Engineered an automated acoustic scanning framework designed for high-resolution non-destructive evaluation (NDE) of submerged targets using water coupling and multi-axis automated positioning.

Mechanical Design & Structural FEA

Designed a custom multi-axis gantry system built for precise, repeatable movements over a fluid coupling tank. Conducted FEA Von Mises stress and static displacement simulations to ensure zero deflection during motion. Performed modal frequency analysis to guarantee structural natural frequencies don't induce acoustic resonance.

Motion Control & Automation

Utilized lead screws and timing belts driven by stepper motors. Controlled via Arduino Uno running custom GRBL firmware and micro-stepping drivers to execute automated G-code grid-scanning paths.

Acoustic Imaging Mechanism

Features a dynamic sensing array with a piezoelectric disk active emitter sending acoustic pulses through water coupling, while high-sensitivity AE transducers capture returning waveforms.

FEA Validation: Von Mises stress, static displacement, and modal frequency verified
Controller: Arduino Uno + GRBL firmware with micro-stepping motor drivers
Acoustics: Piezoelectric emitter disk + high-sensitivity AE receiver array
Architecture: Portable, modular open-frame architecture for on-site research scaling

Acoustic Emissions Gantry System CAD Assembly

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CNC Manufacturing & Tribology Current Project

Click & Pawl Fishing Reel

A precision-machined fly fishing reel engineered for scalable CNC production, extreme environmental thermal stability, and asymmetric drag mechanics.

Materials & Manufacturability

Designed for high-speed CNC milling using lightweight, corrosion-resistant Billet Aluminum 6061 alloy. Optimized tool paths and custom G-code minimize cycle times and material scrap, maximizing commercial viability.

Thermal Dynamics & Clearances

Tolerances are strictly calculated to accommodate thermal expansion coefficient differentials between dissimilar metals, preventing spool binding across extreme 30°C temperature shifts.

Kinematics, Drag & Tribology

Features calibrated spring tension and custom pawl geometry for asymmetric drag (minimal retrieval resistance, smooth payout friction). High-stress rotational points pair Silicon-Bronze with Delrin to eliminate friction and galling at 150 RPM.

Material: Aircraft Grade Billet Aluminum 6061
Thermal Delta: Toleranced for 30°C temperature variations without binding
Tribology Pairs: Silicon-Bronze and Delrin contact surfaces
Operating Speed: Validated up to 150 RPM under heavy drag loading

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Click and Pawl Reel Spool Assembly Render

Fluid Dynamics & CFD

Miniature Wind Tunnel & Streamline Analysis

Design, 3D printing, DAQ programming, and mathematical modeling of pressure differentials and boundary streamlines around a spherical body in turbulent flow.

Fabrication & Electronics DAQ

Engineered a modular PLA 3D-printed wind tunnel with mist reservoir atomizers and a honeycomb flow straightener. Wired an Arduino Uno DAQ to log real-time pressure differential data from a Honeywell sensor alongside fan voltage control.

Mathematical & CFD Modeling

Derived mathematical models in MATLAB to plot polar coordinate streamlines and Bernoulli pressure distribution across the sphere. Calculated Reynolds number Re = 175,740 (turbulent regime). Ran 3D SolidWorks CFD flow trajectory simulations at 10 m/s inlet velocity.

Experimental Evaluation & Upgrades

Validated physical atomizer mist streamlines against MATLAB mathematical plots. Evaluated hardware constraints and proposed next-gen system upgrades (SEK-SDP8xx high-resolution pressure sensor & high-static-pressure fan).