ME Exhaust Structural Assessment

IAC Acoustics (Incat – Hobart, Tasmania, Australia)

IAC Acoustics required thermal-structural analysis of an ME exhaust system for a high-speed ferry (Incat). Avesta Consulting assessed the primary and secondary exhaust silencer and ducting configuration to verify structural integrity of the exhaust system in accordance with relevant standard requirements considering in-service thermal loads and support conditions.

What we did:

  • Performed preliminary gas flow calculations and heat transfer analysis to determine effective heat transfer coefficients for steady state thermal FEA.
  • Performed thermal-structural FEA of exhaust silencers, ducting and supports considering elevated material properties and expansion bellows equivalent stiffness.
  • Modified support conditions to allow unconstrained thermal growth and minimise ducting peak stresses.
  • Verified bolted connection capacities at secondary silencer supports.

Outcome:

Avesta Consulting verified overall structural integrity of the primary and secondary silencers and ducting and identified localised peak stress regions (e.g. bullet cone) which may be subject to low cycle fatigue failure (excluding creep stress relaxation in high temperature regions exceeding 450°C).