Numerical investigation for optimization of spark-ignition internal combustion engine knock by Taguchi-Grey method

Area of Science:

• Internal Combustion Engines
• Combustion Analysis
• Numerical Simulation

Background:

• Engine knock is a critical phenomenon affecting performance and durability.
• Optimizing combustion parameters is essential for efficient and reliable engine operation.
• Understanding parameter contributions to knock tendency and peak pressure is vital for engine design.

Purpose of the Study:

• To numerically investigate engine knock under heavy load conditions.
• To determine the importance and contribution rate of key parameters on peak cylinder pressure and knock tendency.
• To identify optimal operating conditions for minimizing knock and maximizing peak cylinder pressure.

Main Methods:

• Utilized the Taguchi method and grey relational analysis for numerical investigation.
• Employed a design of experiments approach based on Taguchi's L16 orthogonal array.
• Simulated four parameters (compression ratio, spark timing, EGR rate, inlet temperature) at four levels.

Main Results:

• Compression ratio has the highest contribution rate to knock tendency (45.9%) and peak cylinder pressure (40.56%).
• Spark timing and EGR rate also significantly influence knock tendency and peak cylinder pressure.
• Optimal conditions for minimum knock tendency and maximum peak cylinder pressure were determined.

Conclusions:

• Compression ratio is the most influential parameter for controlling engine knock.
• The Taguchi-Grey method effectively determined parameter importance and optimal settings for combustion control.
• The findings provide valuable insights for calibrating engines to prevent knock under heavy load.