Balance measurements on a frigate type ship model. (1st October 2020)

• Record Type: Journal Article
• Authors: Bardera, Rafael; Garcia-Magariño, Adelaida
• Is Part Of: Ocean engineering. Volume 213(2020)
• Publication Date: 2020-10-01
• Subjects: Forces and moments -- Ship stability -- Flight deck -- Air wake -- Balance measurements -- Balance spectra; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2020.107784
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Balance measurements performed by testing sub-scaled ship models determine the global forces and moments acting on the ship, which allows knowing the power required for the ship's movement and provides insight to be applied in the design of the control systems used to steer the ship and to avoid instabilities while sailing. The ship superstructure may produce large separated regions and high air wake turbulence levels resulting in a set of fluctuations of the flow parameters usually determined by measuring velocity or pressure. This paper presents the balance measurement of the aerodynamic forces acting on the ship hull. Aerodynamic forces and moments produced on the ship can be interpreted as an integration of the flow parameters (velocity and pressure distributions) over the ship surface wetted by the air. Balance method provides averaged values and fluctuations of forces coefficients. Aerodynamic environment in the vicinity of a ship is influenced by a large number of factors (atmospheric wind, sea state, ship superstructure, masts, stacks, antennas …) affecting helicopter operations on board ships and their safety during the take-off and landing manoeuvres. Highlights: Force and moment were obtained from balance measurements by wind-tunnel testing on a frigate ship model. The balance was previously characterized dynamically by using the linear system model time invariant method. Aerodynamic forces and moments affect the power requirements and stability during the navigation. Insight of aerodynamic forces and moments may improve control system, contributing to the safe of the ship and its crew. The vortex shedding frequency in the flight deck was similar to that obtained by spectral analysis of the balance signal.