The works in [3 5] propose models which consider fluid torques, where drag forces and torques are evaluated numerically.
The majority of previous modeling approaches for underwater snake robots omit the fluid moments (fluid torques) by considering that their effect on the motion of the robot is negligible [34, 36, 42].
However, including the impact of the fluid torques on the power consumption of the system (see e.g. [4]), will improve the accuracy of the model from a hydrodynamic and energy efficiency point of view.
Moreover, similar study for a 5 link eel-like robot, where the added mass effects and fluid torques are neglected [34], predict that the acceleration should vary: (1) quadratically with gait amplitude, (2) linearly with gait frequency, and (3) accordingly to a weighted sum of sinusoids of the phase shift.
The analysis makes it possible to obtain accurate values of the viscosity of a fluid from torque measurements taken using a sample reservoir.
These drilling operations typically make use of drill strings, which are pipes that transmit both drilling fluid and torque necessary to rotate a drill bit.
As the rotors were directly locked into the shaft, knowing the conversion efficiency of the brushless generator, the fluid dynamic torque was obtained in the PC LabVIEW Controller [8].
Rumbarger, et al. [31], used the established fluid traction torque model to calculate the friction power loss of the bearing roller, cage, and inner and outer ring raceway respectively.
In creeping flow and shear-thinning fluids the torque is independent of the Reynolds number.
In general, the traditional full turbulent modeling leads to an overestimation of fluid-dynamic torque and power.
