Two-Degree Vibration Analysis of a Horizontal Axis Turbine Blade by Finite Differential Methods

Table 2

Natural frequencies of blades.

Rotating speed (rad/s)	0	0.8	10	30
ω1 (FEM)	0.3875	0.4256	1.5765	3.3946
ω1 (FDM)	0.3859	0.4215	1.5552	3.2976
ω2 (FEM)	1.2306	1.2393	2.2422	3.4022
ω2 (FDM)	1.2291	1.2356	2.1287	3.3486
ω3 (FEM)	2.4218	2.4488	4.7605	9.0082
ω3 (FDM)	2.3536	2.3214	4.4561	8.6540
ω4 (FEM)	4.3346	4.3503	5.6395	12.039
ω4 (FDM)	4.2369	4.5123	6.1420	11.204
ω5 (FEM)	7.3653	7.3922	10.498	18.218
ω5 (FDM)	7.4141	7.4345	10.785	17.214
ω6 (FEM)	10.549	10.555	11.365	20.293
ω6 (FDM)	10.985	11.241	11.754	22.314