This paper reports experimental measurements of the hydrodynamic forces acting on a low drag submersible. The model was manufactured using standard, cost-effective methods without undue attention paid to the roughness or waviness of the model's surface. It was seen, using flow visualization techniques, that the laminar boundary layer extended over 70 % of the vehicle length; furthermore, no separation of the flow was seen over the remaining 30 % of the body. Hydrodynamic forces were measured, and a significant reduction in drag was found compared with standard turbulent submersible shapes. The low drag performance was quite resilient to changes in incidence, showing a large drag 'bucket' for angles of incidence between plus/minus 4 deg. With the addition of a set of cruciform fins at the rear of the body, incorporating control surfaces, it was found that for a centre of gravity position forward of 41.3 % of the body length, the vehicle would be statically stable both stick-free and stick-fixed. Finally, using a pitot tube wake rake the velocity profile of the boundary layer at the propeller location was found to be that of an attached, turbulent boundary layer closely matching 5.35-1 power law. The importance of full interference measurement tests to allow for the support strut effects is clearly demonstrated.
Wind tunnel experiments on a fully appended laminar flow submersible for oceanographic survey
Windkanalexperimente zu einer voll ausgebildeten laminaren Umströmung einer tieftauchfähigen unbemannten Kapsel zur Meereserkundung
Ocean Engineering ; 22 , 2 ; 207-221
1995
15 Seiten, 16 Bilder, 4 Tabellen, 8 Quellen
Aufsatz (Zeitschrift)
Englisch
Hydrodynamik , Windkanal , praktische Untersuchung , Ozeanographie , laminare Grenzschicht , Strömungswiderstand , Modellversuch , Herstellkosten , Strömungstrennung , Eintrittswinkel , Rippe (Bauteil) , statische Stabilität , Pitot-Rohr , Strömungsprofil , turbulente Grenzschicht , Strömungsvisualisierung
Laminar-Flow Wind Tunnel Experiments
NTIS | 1989
|Laminar-flow wind tunnel experiments
NTRS | 1989
|Laminar-Flow Instrumentation for Wind-Tunnel and Flight Experiments
Online Contents | 1993
|