Dynamics Modeling and Validation of Coaxial Lifting Rotors

doi:10.16183/j.cnki.jsjtu.2021.044

Abstract

Abstract:

The dynamics model for coaxial lifting rotors can be used to study the controller design and flight simulation for coaxial-rotor aerial vehicles. However, both the computational efficiency and the accuracy should be considered. First, the computational model of the induced velocity of lifting rotor everywhere including the wake region is derived based on adjoint theorem. Then, the finite state dynamics model for coaxial lifting rotors with wake skew considered is developed by extending the finite state inflow model for single rotor. Finally, the equations for calculating the thrust of coaxial lifting rotors in the hover condition are given, and the test is conducted. The results show that the computational complexity of the proposed dynamics model for coaxial lifting rotors is acceptable, and the computational thrusts are almost close to the test results when the rotational speed is within a certain range, which can also reflect the trend of the thrust lost for coaxial lifting rotors.

Key words: coaxial lifting rotors, dynamics modeling, finite-state inflow, flow field interaction

CLC Number:

V211
O39

HU Jinshuo, HUANG Jianzhe. Dynamics Modeling and Validation of Coaxial Lifting Rotors[J]. Journal of Shanghai Jiao Tong University, 2022, 56(3): 395-402.

Figures/Tables 8

Fig.1

Tab.1

Fig.2

Fig.3

Tab.2

Thrusts at different rotor speeds for single rotor

ω/(r·min^-1)	F/g	$F ~$ /g	e_F/g
3000	65.7	111.80	46.10
3500	128.0	152.23	24.23
4000	200.0	198.81	-1.19
5000	393.0	310.59	-82.41

Tab.2

Fig.4

Fig.5

Tab.3

Thrusts at different rotor speeds for coaxial lifting rotor

ω/(r·min^-1)	F^(l)/g	$F ~ (1)$ /g	$e F (l)$ /g	F^(u)/g	$F ~ (u)$ /g	$e F (u)$ /g
1700	39.30	33.11	-6.19	12.75	20.99	8.24
3000	129.21	103.11	-26.10	64.34	65.36	1.02
3700	227.02	156.87	-70.15	135.82	99.44	-36.38
4400	307.86	221.80	-86.06	216.77	140.60	-76.17
4900	395.95	275.13	-120.82	276.72	174.41	-102.31

Tab.3

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r/mm	c/mm
5.0	13.0
25.4	20.8
50.8	29.7
71.2	32.5
91.6	31.0
117.0	24.8