Computational Fluid Dynamics (CFD) 


1. Why CFD is Essential to “Process Studies”

  • 3-D physics in 1-D world: Pipelines, separators, pumps, compressors, mixers, flare tips, SCR exhausts, hydrate-jets, blowdown plumes – all contain recirculation, swirl, separation, temperature stratification, or transient vortices that steady-state 1-D codes cannot resolve.
  • CAPEX deflection: A single CFD-driven optimisation (eliminating a dead zone, reducing pressure drop 15 %, or correctly sizing a flame stabiliser) typically saves 5–20× the study cost.
  • Risk reduction: Predicting erosion hot-spots, vibration excitation, LNG rollover, or flammable cloud dimensions provides defensible inputs to safety cases (QRA, Dropped Object, FERA, SIL).
  • Digital twin seed: High-fidelity meshes become the physics core for real-time twins and operator training simulators.

2. Service Scope – What We Deliver


Category Typical Deliverables
Single-phase flow Pressure drop, velocity maps, shear rates, mixing time, vortex location
Multiphase Gas-liquid distribution, droplet size, entrainment fraction, hold-up, slug genesis
Reactive / combustion Flame shape, temperature field, NOx, CO, soot, blow-off margin, radiation load
Particle & erosion Sand, catalyst, ice, corrosion product tracks; erosion rate maps (DNV RP O501)
Fluid-structure interaction One-way force spectra → mechanical team for fatigue; two-way if large deflection
Transient / dynamic Cool-down, start-up, surge, shut-in, ESD blowdown, relief valve lift, spill dispersion
Adjoint / shape optimisation Automated geometry morphing to minimise pressure drop, maximise mixing, reduce mass

3. Software & Hardware Stack (2025)

  • Ansys Fluent & CFX – general purpose, poly-hexcore, overset, adjoint, combustion, DPM, DEM, population balance
  • Siemens Simcenter STAR-CCM+ – multiphase VOF, LMP, DEM, conjugate heat transfer (CHT), overset motion, adjoint
  • OpenFOAM® – custom solvers (compressible reacting, non-Newtonian, hydrate icing, CO₂ depressurisation)
  • CONVERGE™ – detailed IC-engine & flare combustion, automatic meshing, detailed chemistry
  • gPROMS & AFT Impulse – 1-D + 3-D coupling for long pipelines
  • HPC Cloud: 1,200+ cores on-demand, InfiniBand, Lustre – typical turn-around 24–72 h for 30–50 M cell models.

4. Proven Workflows – Quality & Audit Trail

  1. Scope & KPI lock – ΔP, residence time, erosion rate, T<sub>, cloud extent, noise dB, etc.
  2. 1-D / hand calc sanity check – identify controlling physics, expected magnitude.
  3. Geometry prep & defeaturing – CAD import, 100–300 µm surface mesh, curvature & proximity refinement.
  4. Mesh independence study – 3 successive refinements; GCI ≤ 5 % on primary KPI.
  5. Physics & BC lock – turbulence (k-ω SST, BSL, LES), multiphase (VOF, Euler-Euler, LMP), radiation (DO, MC), reactions (PDF, FGM, finite-rate), transient time-step < 1/10 Courant.
  6. Verification vs. data – flow loop, plant test, PIV, concentration probe, erosion coupon, IR camera.
  7. Parametric / DOE / adjoint – automate geometry variants; deliver Pareto frontier.
  8. Report & peer review – ASME V&V 40-2018 compliant; independent technical review; model archived for client reuse.

5. 2025 Focus Areas & Case Snapshots

A. Multiphase Pipe Components

  • Slug-catcher inlet vane – reduced droplet cut-size 35 % → smaller vessel, $1.2 M saved.
  • Subsea Wye 10″×6″ – eliminated dead zone, cut sand hold-up 60 %, pressure drop +0.07 bar (acceptable).
  • Pump suction bellmouth – optimised profile, NPSHr margin +0.8 m, power draw –2.1 %.

B. Separation Internals

  • Inline cyclone + vane pack – CFD → pilot loop → field: 98 % > 10 µm removal at 12 m s⁻¹; 30 % smaller footprint.
  • Produced water hydrocyclone cluster – adjoint shape → 3-D printed insert; oil-in-water outlet 40 ppm → 18 ppm.

C. Reacting Flow / Flare & Thermal

  • High-pressure CO₂-rich flare tip – LES + PDF combustion; radiation at 30 m reduced 28 %, noise –6 dB, CO < 20 ppm.
  • Fired-heater burners switch to H₂-rich gas – predicted flame shorting, modified swirl angle; NOx < 40 ppm, stability margin +40 %.

D. Erosion & Particle Dynamics

  • Choke insert tungsten-carbide optimisation – DPM + Finnie erosion; life extended 2.8×, CAPEX –22 %.
  • Subsea bend + sand – LMP particle tracking; erosion rate map fed to RBI, inspection interval extended 1.6×.

E. Transient / Safety

  • CO₂ dense-phase blowdown – non-equilibrium HRM solver; predicted –78 °C at 2 km, enabled selective LTCS upgrade, saved $8 M CAPEX.
  • LNG spill on water – CFD with solidification & rapid-phase-transition model; cloud 150 m LFL, informed hazard range.

6. Validation & Experimental Back-Up

  • High-pressure flow loops (NTNU, SINTEF) – 1″–4″, 100 bar, multiphase, real fluids
  • PIV / LDA / high-speed imaging – droplet size, velocity fields, vortex core identification
  • Erosion test rigs – sand, catalyst, ice, CO₂-hydrate particles at 10–80 m s⁻¹; DNV calibration
  • Flare radiation & noise field tests – 30 m, 60 m, 120 m IR cameras & acoustic arrays
  • Literature & open-data benchmarks – T-junction, cyclone, burner, backward-facing step, NACA 0015, etc.
All models include a validation statement that links simulation KPIs to measured quantities with stated uncertainty bands.

7. Typical Project Roadmap & Deliverables


Phase Duration Deliverable
Kick-off & KPI freeze 1–2 d Scope memo, success metrics
CAD & mesh independence 1 wk Clean geometry, 3 meshes, GCI report
Baseline CFD 1 wk First results, trend check vs. 1-D
Parametric / DOE 1–2 wk 5–20 geometry/operating variants
Optimisation & ranking 1 wk Pareto set, sensitivity chart
Validation vs. data 1 wk Calibration report, uncertainty
Final report & peer review 3–5 d ASME V&V 40-2018 compliant document, archived solver files, viewer-state, animations

8. Benefits to Client Projects (2024-2025)

  • Subsea compressor suction bend – pressure drop –18 % → 0.9 bar less → 600 kW power saved → $450 k/yr OPEX reduction
  • Gas-liquid inlet vane – droplet cut-size 35 % smaller → separator vessel diameter –1 m → $1.2 M CAPEX saved
  • CO₂ trunkline blowdown – non-equilibrium CFD predicted –78 °C vs –46 °C HEM → selective LTCS upgrade only on final 200 m → $8 M CAPEX saved vs full LTCS line
  • Produced water hydrocyclone – adjoint optimisation → oil-in-water 40 ppm → 18 ppm → client meets new discharge limit without tertiary treatment plant (~$6 M avoided)
  • High-pressure choke erosion – DPM + Finnie → tungsten-carbide insert redesign → life 2.8×, cost –22 %, downtime –40 %

9. Getting Started – Typical Enquiry Checklist

  1. What is the business pain? (ΔP too high, erosion, poor mixing, flame impingement, noise, cloud drift, thermal cycling, …)
  2. Geometry availability – native CAD, neutral STEP, laser scan, or concept sketch?
  3. Operating envelope – P, T, phases, composition, flow range, transient vs. steady
  4. Success KPI – max ΔP, min residence, erosion rate, T_max, dB, LFL cloud, NOx ppm, etc.
  5. Experimental data – lab, pilot, plant test, PIV, IR, concentration, erosion coupons?
  6. Deliverable format – report only, native case file, digital twin link, operator training movie?
  7. Schedule & gate reviews – FEL-2, FEL-3, detailed design, operational troubleshooting?

10. Why CORMat Group for CFD?

✅ Integrated Process Insight – CFD is embedded within flow assurance, process simulation, mechanical design, safety & economics; not a stand-alone “black-box”.
✅ Full spectrum – single-phase mixing to reacting LES, hydrate-icing, non-Newtonian slurries, full-scale plant items.
✅ Validation culture – every model linked to measured data; uncertainty quantified; ASME V&V 40-2018 compliant.
✅ Digital continuity – same mesh/physics feeds OLGA, Symmetry, P&ID, cost, schedule, and operator-training twins.
✅ Commercial agility – on-demand HPC, fixed-price or T&M, rapid turnaround (days), peer-review included.
Bring your toughest flow problem – we’ll model it, measure it, and make it better.