Experimental and numerical simulations of simple frigate with suction flow control over the deck. (15th September 2021)

• Record Type: Journal Article
• Authors: Bardera, R.; Matías, J.C.; Barroso, E.
• Is Part Of: Ocean engineering. Volume 236(2021)
• Publication Date: 2021-09-15
• Subjects: Air wake -- PIV -- Experimental -- Numerical -- Frigate -- Flow control; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109464
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: The air wake generated behind a frigate superstructure is a very complex and unsteady three-dimensional flow characterized by highly turbulent flow structures with great velocity gradients that result in flow separation over the flight deck where helicopter operations take a significant role. Naturally, this turbulent flow should be removed or, at least, reduced as maximum as possible to avoid accidents during the interaction between frigates and helicopters. This paper involves experimental and numerical analysis on a simple frigate model (SFS2) to understand and simulate the adverse effect of the turbulent flow of the air wake over the deck and tries to minimize it as with active flow control. The experimental study has been performed in the Low Speed Wind Tunnel nº1 of Instituto Nacional de Técnica Aeroespacial ''Esteban Terradas'' (INTA) with Particle Image Velocimetry (PIV) to obtain the velocity field over the flight deck. The frigate has been tested for the headwind condition of 0° (wind aligned with the flight deck) with a velocity of 10 m/s. The active flow control consists on generating suction on the flight deck by a mesh of holes. Several configurations of this suction mesh have been studied according to the diameter and location of holes and suction intensity. The suction mesh configuration with the highest diameter and flow rate presents the greatest aerodynamic improvement. The low-speed area over the deck is reduced from 36% to a minimum of 3%. Highlights: Experimental and numerical investigation of airflow on a Simple Frigate Shape wind model. Design and study of the flow control system based on the flow suction. Comparative study of the base flow on the frigate model versus modified flow by the suction flow control system for different configurations. Parametric study of results for different air flow rates and locations of suction. Concordance between numerical and wind tunnel results investigated by a comparative analysis.