To operate efficiently, power plants must optimize the aerodynamic and mechanical performance of fan and duct systems. Dynamics problems, such as foundation resonance amplification, acoustic resonance, and panel and bellows damage, must be resolved as quickly as possible to minimize damage. Southwest Research Institute (SwRI) has more than 20 years of experience in troubleshooting power plant exhaust and air supply system problems.

Typical Fan and Duct Problems

Various fan and duct system problems include:

• Shaft critical speed operation

• Foundation resonance amplification

• Disk wobble from center-plate flexibility

• Shaft thermal bow

• Excessive noise

• Shaft and impeller cracking

• Unstable variable speed drives

• Fan rotating stall

• Flow-induced vibration

• Blade fatigue failure

Diagnostic Services

	To eliminate blade fatigue caused by resonance, engineers combine modal testing with strain gage telemetry.

To identify and resolve dynamic fan and duct problems quickly, a comprehensive series of quick-response SwRI engineering services is available, including:

• Troubleshooting and consultation

• In situ multi-plane balancing

• Modal testing of shafts

• Modal testing of impellers

• Foundation shaker testing

• Structure shaker testing

• Duct acoustic modes mapping

• Structural modes mapping

• Shaft strain telemetry

• Blade strain telemetry

  	Acoustic resonance in an exhaust duct system, which can cause panel and bellows damage, is identified by SwRI staff.

• Remote diagnostic monitoring

• Computational fluid dynamics analysis

• Finite element analysis

• Rotor dynamic modeling

• Duct acoustic modeling

• Noise measurements

• Vibration measurements

• Pulsation measurements

• Performance testing

• Performance diagnostics

For more information about our machinery vibration services, our fan and duct dynamics capabilities, or how you can contract with SwRI, please contact Klaus Brun, Ph.D., at kbrun@swri.org or (210) 522-5449.

machineryvibration.swri.org