Expert CFD & Engine Cycle Modeling for High-Frequency 2-Stroke Engine

About the project

We are looking for a Senior Engine Simulation / CFD Expert to mathematically model the working cycle, design the gas exchange architecture, and optimize combustion before we proceed to prototyping. Our primary goals for this power unit are maximum fuel efficiency (lowest BSFC) and minimum exhaust emissions. Key Technical Specifications: Engine Type: 2-Stroke engine. Non-sinusoidal kinematics (custom piston motion profile) with a dynamically variable compression ratio. Target Mechanical Power: 3.2 kW (at the output rod). Operating Frequency: 150 Hz (9,000 cycles/min). Working Stroke: Dynamic, minimum stroke is ~40 mm. Fuel Delivery: Direct Injection (DI). Extremely short time window for droplet breakup, evaporation, and mixing (< 2 ms). Aspiration: External forced induction (supercharged). The specific scavenging layout, port geometry, and valve configuration are open and should be proposed by you based on efficiency goals. Scope of Work: 1. 1D Concept & Gas Dynamics: Propose and justify the scavenging architecture (uniflow, loop, etc.). Perform 1D Time-Area calculations to size the ports and determine the required cylinder bore to achieve 3.2 kW at 150 Hz / 40 mm stroke. 2. 3D CFD Scavenging Simulation: Build a 3D model using moving mesh (AMR) to simulate gas exchange. Optimize the port and piston crown geometry to maximize Trapping Efficiency and Scavenging Efficiency while minimizing pumping losses. 3. Combustion & Multiphase DI Modeling: Simulate the Direct Injection process and combustion chemistry. Optimize injection timing and turbulence (Swirl/Tumble) to ensure complete combustion and low emissions. Expected Deliverables: Optimized 3D CAD geometry for the cylinder liner (ports) and piston crown. Performance report including estimated BSFC, Indicated Thermal Efficiency, and emission trends. Required supercharger specifications (absolute pressure and mass flow). Data Arrays: P-V diagrams (cylinder pressure profiles vs. piston position) at various fuel loads. This is critical for our control system architecture. Required Skills & Software: Deep understanding of 2-stroke scavenging, unsteady gas dynamics, and custom piston motion dynamics. Proficiency in advanced engine simulation software with moving mesh and combustion models (e.g., CONVERGE CFD, Ansys Forte, OpenFOAM). Experience with 1D/3D coupling (GT-POWER, Ricardo WAVE, or EngMod2T) is highly preferred. How to Apply: Please start your proposal with the word "SCAVENGING" so I know you have read the full description. In your cover letter, briefly mention which software stack you plan to use to handle the moving mesh and the 150 Hz Direct Injection simulation.

Skills required