CFD / Airflow Simulation Engineer - For Residential air Purifier

We are validating two alternative internal airflow-path designs for a 2,000 CFM-class residential air-purification enclosure before committing to physical fabrication. We need a freelance CFD / airflow simulation engineer to run comparative flow simulations and tell us, with data, which design performs better and by how much. THE TWO DESIGNS - Design A (current, internally approved): a compact enclosure where a 4-stage filter stack (1 pre-filter + 3 HEPA H14 banks, 551 x 580mm face) sits beside a 400mm-class backward-curved centrifugal EC fan, requiring airflow to make a 90-degree turn between the filter stack and the fan inlet. - Design B (concept, first-pass, not yet CAD-validated): a taller, straight-through enclosure where the same filter stack sits below the same fan, air flowing straight up through the filters into the fan inlet with no turn. Both designs use the identical filter stack and the identical fan. Full vendor performance curve data is supplied (free-delivery ~3,822 m3/h; ~150 Pa at ~3,334 m3/h at full speed, 5 speed settings total). Dimensioned drawings (side + plan view, mm), fan curve data, and filter-loading assumptions are all in the attached brief. WHAT WE NEED 1. A CFM-vs-filter-loading curve for EACH design, at minimum: clean, 25% loaded, 50% loaded, 75% loaded (our internal reference pressure-drop multipliers are 1.0x / 1.4x / 2.0x / 3.5x -- treat as a starting assumption, not fixed). 2. A pressure-drop breakdown by component (filter stack, plenum/turn, fan) for each design at each loading state. 3. A side-by-side comparison chart/table: Design A vs Design B, CFM delivered at each loading state, plus % difference. 4. A short written engineering opinion on how much CFM (if any) is lost to Design A's 90-degree turn (fan-inlet "system effect") versus Design B's straight-through path, and whether that loss is significant enough to justify a taller enclosure. We are NOT asking for a redesign -- only a simulation-based comparison of the two designs as given, to inform whether we proceed with Design A as-is or reconsider Design B before a manufacturing vendor builds a physical sample. DELIVERABLES - CFD simulation setup/files (tool of your choice -- please state which in your proposal) - A short written report (PDF or DOCX) covering the 4 items above, with charts - Raw result data (CSV or similar) if convenient TIMELINE Looking to complete this within 1-2 weeks of award, ahead of finalizing a manufacturing decision. Please review the attached technical brief for full dimensions, fan curve data, filter specs, and known open items before submitting a proposal.