Energy & Modelling Research Group
Chaired by Dr. Mahmoud Shaaban at Nile University, our research group investigates nonlinear aeroacoustic source mechanisms, fluid-structure instabilities, and high-amplitude thermoacoustic energy conversion through coupled experimental diagnostics and high-fidelity continuum modeling.
STDF Thermoacoustic Energy Conversion Project
Project ID: 53113 EGP 1,400,000 • 2026 – 2028 Development of an Experimentally-Validated Modeling Framework for Nonlinear Energy Dissipation in High-Amplitude Thermoacoustic Devices
Thermoacoustic devices convert thermal energy directly into high-intensity acoustic work without moving pistons or environmentally harmful refrigerants. Achieving commercially competitive power densities, however, drives pressure oscillations into strongly nonlinear regimes exceeding 10% of the mean gas pressure.
This STDF-funded program establishes a validated numerical-experimental modeling framework quantifying three coupled dissipation mechanisms:
- Nonlinear minor losses and coherent vortex shedding at stack, regenerator, and cylindrical resonator discontinuities.
- Acoustic streaming convection (Rayleigh and jet-driven recirculation) distorting axial temperature gradients.
- Harmonic distortion cascades transferring energy from the fundamental standing wave into parasitic higher harmonics.
Experimental & Computational Infrastructure
Integrating precision wind-tunnel laser diagnostics and dynamic force measurements with unsteady CFD/FEA continuum modeling.
Aeroacoustic Wind Tunnels, Laser PIV & Dynamic Force Rigs
- Subsonic Aeroacoustic Wind Tunnels: Low-turbulence closed test sections instrumented for bluff-body lock-in and cavity resonance.
- Phase-Resolved Particle Image Velocimetry (PIV): Synchronized dual-pulsed Nd:YAG laser optics, CCD imaging, and acoustic phase triggering for coherent wake reconstruction.
- Dynamic Force & Acoustic Arrays: High-bandwidth piezoelectric load cells, flush-mounted microphone arrays, and pipeline acoustic admittance rigs.
Unsteady CFD, Howe’s Analogy & Coupled FEA
- Unsteady CFD (OpenFOAM & ANSYS Fluent): Compressible Large Eddy Simulation (LES) and URANS resolving shear-layer roll-up and three-dimensional vortex cores.
- Howe’s Aeroacoustic Energy Corollary: Volumetric integration of vorticity, flow velocity, and acoustic particle velocity to map spatial acoustic energy sources and sinks.
- Coupled FEA & Wavelet Diagnostics: ANSYS Mechanical structural modal solvers paired with continuous wavelet transforms (CWT) for transient frequency tracking.
Selected Aeroacoustic & FSI Research Campaigns
Representative experimental and numerical discoveries spanning multi-cylinder acoustic synchronization, bluff-body modal coupling, and nonlinear wake-induced vibration.
Acoustic Mode Lock-In & Wake Synchronization in Tube Arrays
Cross-flow over side-by-side and inline cylinder arrangements excites standing transverse acoustic duct modes capable of synchronizing vortex shedding across aerodynamically isolated wakes. Phase-locked Particle Image Velocimetry (PIV) and periodic Reynolds stress decompositions reveal how odd and even acoustic mode shapes reorganize near-wake vorticity and dynamic lift.
Aspect Ratio, Incidence Angle & Shear-Layer Coupling
Rectangular prisms and sharp-edged bluff bodies exhibit distinct impinging-shear-layer and leading-edge separation instabilities depending on chord-to-thickness ratio and flow incidence. Coupled microphone waterfall spectra and phase-resolved velocity fields quantify lock-in onset thresholds and modal energy exchange across first and higher-order acoustic cross-modes.
Self-Excited Cylinder Vibrations & Phase-Lag Hysteresis in Wakes
Downstream cylinders immersed in unsteady upstream wakes undergo large-amplitude nonlinear oscillations governed by reduced velocity, tandem spacing ratio, and instantaneous lift-displacement phase trajectories. Tracking figure-eight and elliptical hysteresis loops between transverse displacement and lift coefficient isolates energy-harvesting versus damping regimes.
Research Grants, Fellowships & Academic Awards
Post-Doctoral Fellowship
Postdoctoral fellowship supporting experimental FSI wind tunnel campaigns, pipeline valve finite element stress analysis, and pulsating flow-acoustic simulations.
Ontario Trillium Scholarship (OTS)
Premier four-year provincial doctoral scholarship awarded to top international Ph.D. researchers in Ontario demonstrating exceptional research merit.
Graduate Student Research Excellence Award
Recognized for outstanding doctoral research output in experimental aeroacoustics and flow-induced vibration.
Graduate Student Conference Travel Award
Competitive travel grant supporting presentation of pipeline acoustic admittance and Helmholtz suppression research.
Design and Implementation of a Renewable Energy Cycle Educational Stand
ASHRAE-funded senior engineering project designing and building an instrumented renewable energy cycle educational test stand at Cairo University.
Award of Excellence for Engineering Students
Undergraduate academic merit distinction awarded to top-ranked engineering students in Egypt.
Open Research Positions Opportunities for M.Sc., Ph.D. & Capstone Scholars
We recruit analytical and experimentally minded graduate candidates and senior undergraduate capstone teams with strong foundations in fluid mechanics, heat transfer, and mechanical vibrations, alongside proficiency in Python, MATLAB, C++, OpenFOAM, or ANSYS.