Entropy-based detached-eddy simulation of the airwake over a simple frigate shape

Zhao Rui,Rong Ji-Li,Zhao Peng-Cheng,Li Hai-Xu

doi:10.1177/1687814015616930

Abstract

The wind past the ship superstructure produces an unsteady turbulent airwake which has a significant effect on aircraft performance and consequently pilot workload during ship landing process. Computational fluid dynamics simulations of a generic simple frigate shape ship airwake have been performed using the entropy-based detached-eddy simulation method. The results were compared with the steady-state Reynolds-averaged Navier–Stokes calculations and the wind tunnel data, indicating the capability of entropy-based detached-eddy simulation to resolve the unsteady large-scale turbulent features. An analysis of the airwake flow topology at headwind condition highlights the vortex pairing process which dominates the flowfield above the deck. Additionally, the influence of hangar-door state (open, closed or half-open) on the airwake was also investigated in detail. Determination of this complex flow can assist in the definition of safe ship–helicopter operating limits and future ship design.

Highlights

One of the most demanding of all piloting tasks is to land a helicopter on the flight deck of a moving nonaviation ship, such as the frigate, destroyer, and cruiser
A typical ship structure resembles the back-facing step, which has a massive separated region in its wake at Reynolds number ranges of order of 104 and greater.26Figure 7 shows the flow pattern on the deck of SFS at relative wind angle of 0°
A large recirculation region behind the hangar is produced by the flow incoming to the flight deck from the sides of the ship and causing counter-rotating vortices on each side of the recirculation region

Summary

Introduction

One of the most demanding of all piloting tasks is to land a helicopter on the flight deck of a moving nonaviation ship, such as the frigate, destroyer, and cruiser. The flow past SFS configuration has been experimentally studied using oil film visualization, PIV, and LDA, respectively.[7] Flight deck is located downstream the hangar and dedicated to the helicopter operations as a helideck.

Results

Conclusion