Engineering topics

Hoque, M. S.

Publications and source records attributed to Hoque, M. S..

2 records

NASA NTRS1990

Simulated rotor test apparatus dynamic characteristics in the 80- by 120-foot wind tunnel

A shake test was conducted in the 80 by 120 foot Wind Tunnel at NASA Ames Research Center, using a load frame and dummy weights to simulate the weight of the NASA Rotor Test Apparatus. The simulated hub was excited with broadband random excitation, and accelerometer responses were measured at various locations. The transfer functions (acceleration per unit excitation force as a function of frequency) for each of the accelerometer responses were computed, and the data were analyzed using modal analysis to estimate the model parameters.

Hoque, M. S.↗

NASA NTRS1989

An electroviscous damper

A new type of vibration damper for rotor systems was developed and tested. The damper contains electroviscous fluid which solidifies and provides Coulomb damping when an electric voltage is imposed across the fluid. The damping capacity is controlled by the voltage. The damper was incorporated in a flexible rotor system and found to be able to damp out high levels of unbalanced excitation. Other proven advantages include controllability, simplicity, and no requirement for oil supply. Still unconfirmed are the capabilities to eliminate critical speeds and to suppress rotor instabilities.

Nikolajsen, Jorgen L.↗