An Experimental Analysis of the Fluid Dynamic Efficiency of a Production Spark-Ignition Engine during the Intake and Exhaust Phase

Table 5

Influence of the throttle angle on the absolute and mean flow coefficients. Intake system.

Throttle angle, 𝐹	90°	70°	50°	40°	30°
Absolute flow coefficient, 𝐶𝑓Abs	0.291	0.289	0.277	0.246	0.185
Absolute discharge coefficient, 𝐶𝑑Abs	0.469	0.466	0.448	0.407	0.321
Mean flow coefficient, 𝐶𝑓Mean	0.330	0.328	0.313	0.253	0.202
Mean discharge coefficient, 𝐶𝑑Mean	0.427	0.424	0.406	0.373	0.272
Maximum flow coefficient, 𝐶𝑓Max	0.376	0.372	0.355	0.304	0.217
Maximum discharge coefficient, 𝐶𝑑Max	0.559	0.553	0.537	0.507	0.459