The Technique of MIEELDLD in Computational Aeroacoustics

Table 3

Comparing the dispersive and group velocity properties for two spatial methods ZINGG and ZINGG-NEW in terms of number of points per wavelength (to 4 d.p).

Accuracy	Method	Max. value of 𝜃ℎ	No. of pts per wavelength
|𝜃^∗ℎ−𝜃ℎ|𝜋≤5×10^−3	ZINGG	1.2239	5.1339
|𝜃^∗ℎ−𝜃ℎ|𝜋≤5×10^−3	ZINGG-NEW	1.2579	5.1258
|𝜃^∗ℎ−𝜃ℎ|𝜋≤5×10^−4	ZINGG	0.9163	6.8575
|𝜃^∗ℎ−𝜃ℎ|𝜋≤5×10^−4	ZINGG-NEW	0.9988	6.2904
||||𝑑𝑑(𝜃ℎ)(𝜃^∗ℎ)−1.0||||≤5×10^−3	ZINGG	0.7885	7.9686
||||𝑑𝑑(𝜃ℎ)(𝜃^∗ℎ)−1.0||||≤5×10^−3	ZINGG-NEW	0.8471	7.4176
||||𝑑𝑑(𝜃ℎ)(𝜃^∗ℎ)−1.0||||≤5×10^−4	ZINGG	0.6200	10.1341
||||𝑑𝑑(𝜃ℎ)(𝜃^∗ℎ)−1.0||||≤5×10^−4	ZINGG-NEW	0.7379	8.5152