Exam Question
(a) What are the causes of Turbocharger surging? How is it indicated to the watchkeeper? (8)
(b) What are the possible remedial action? (4)
(c) What are the reasons for excessive fouling of the turbocharger? (4)
Class 4 (4th Engineer)
MEKM
📅 Aug 2024
Reference Answer
### (a) Causes of Turbocharger Surging and Indications (8 Marks)
**Definition of Surging:**
Surging is a phenomenon of aerodynamic instability occurring in the compressor side of the turbocharger. It is characterized by the breakdown of steady flow, leading to a complete reversal of air flow through the compressor. This occurs when the compressor's delivery pressure is too high for the mass flow rate required by the engine, causing the operating point to cross the 'surge line' on the compressor performance map. The cycle involves flow reversal, a drop in scavenge manifold pressure, restoration of forward flow, and a rapid pressure rise, repeating at a high frequency (e.g., 3-10 Hz).
**Causes of Surging:**
**Definition of Surging:**
Surging is a phenomenon of aerodynamic instability occurring in the compressor side of the turbocharger. It is characterized by the breakdown of steady flow, leading to a complete reversal of air flow through the compressor. This occurs when the compressor's delivery pressure is too high for the mass flow rate required by the engine, causing the operating point to cross the 'surge line' on the compressor performance map. The cycle involves flow reversal, a drop in scavenge manifold pressure, restoration of forward flow, and a rapid pressure rise, repeating at a high frequency (e.g., 3-10 Hz).
**Causes of Surging:**
Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.
Prepare on Android — MeoMock on Google Play