Propulsion of a fin whale ( Balenoptera physalus) : why the fin whale is a fast swimmer

1989 ◽  
Vol 237 (1287) ◽  
pp. 175-200 ◽  

Measurements of an immature fin whale {Balaenoptera physalus), which died as a result of entrapment in fishing gear near Frenchmans Cove, Newfoundland (47° 9' N, 55° 25' W), were made to obtain estimates of volume and surface area of the animal. Detailed measurements of the flukes, both planform and sections, were also obtained. A strip theory was developed to calculate the hydrodynamic performance of the whale’s flukes as an oscillating propeller. This method is based on linear, two-dimensional, small-amplitude, unsteady hydrofoil theory with correction factors used to acount for the effects of finite span and finite amplitude motion. These correction factors were developed from theoretical results of large-amplitude heaving motion and unsteady lifting-surface theory. A model that makes an estimate of the effects of viscous flow on propeller performance was superimposed on the potentialflow results. This model estimates the drag of the hydrofoil sections by assuming that the drag is similar to that of a hydrofoil section in steady flow. The performance characteristics of the flukes of the fin whale were estimated by using this method. The effects of the different correction factors, and of the frictional drag of the fluke sections, are emphasized. Frictional effects in particular were found to reduce the hydrodynamic efficiency of the flukes significantly. The results are discussed and compared with the known characteristics of fin-whale swimming.

1989 ◽  
Vol 26 (03) ◽  
pp. 192-201 ◽  
Author(s):  
Neil Bose ◽  
Peter S. K. Lai

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.


2017 ◽  
Vol 3 ◽  
Author(s):  
LAETITIA LEMPEREUR ◽  
MORGAN DELOBELLE ◽  
MARJAN DOOM ◽  
JAN HAELTERS ◽  
ETIENNE LEVY ◽  
...  

SUMMARY On 9 November 2015, a juvenile male fin whale of 11·60 m length was observed on the bulb of a merchant vessel in the Channel Terneuzen – Ghent (The Netherlands – Belgium). A severe parasitosis was present in the right heart ventricle and caudal caval vein. Parasites were identified as Crassicauda boopis based on macroscopic and microscopic observations. The sequence of the 18S rRNA gene obtained from the parasite samples was 100% similar to the sequence of the 18S rRNA gene from Crassicauda magna available on GenBank. While adults of C. boopis and C. magna are morphologically distinct and found at different locations in the body, the molecular analysis of the 18S rRNA gene seems insufficient for reliable species identification. Although numerous C. boopis were found, the cause of death was identified as due to the collision with the ship, as suggested by the presence of a large haematoma, and the absence of evidence of renal failure. The young age of this whale and the absence of severe chronic reaction may suggest that the infestation was not yet at an advanced chronic stage.


1988 ◽  
Vol 66 (2) ◽  
pp. 534-537 ◽  
Author(s):  
Caroline M. Pond ◽  
Christine A. Mattacks

The gross mass, mean adipocyte volume, and hexokinase and phosphofructokinase activities of blubber and internal adipose tissue were measured from fin whales (Balaenoptera physalus) caught in the North Atlantic west of Iceland. Fin whale adipocytes are smaller but more numerous than predictions from allometric equations relating adipose tissue structure to body mass, but the deviations are no greater than those of some terrestrial mammals, including humans. Significant activity of the glycolytic enzymes was measured from all adipose tissue samples except those around the eyeball; the activities of hexokinase and phosphofructokinase measured at room temperature are only slightly lower in the blubber than in the internal adipose depots. There was little evidence for metabolic correlates of the site-specific differences in the structure and chemistry of blubber. The highest capacity for glucose utilization was measured in adipose tissue from depots in the neck and the thorax, both of which may contain thermogenic tissue in neonates.


2014 ◽  
Vol 74 (1) ◽  
pp. 137-144 ◽  
Author(s):  
LL Wedekin ◽  
MR Rossi-Santos ◽  
C Baracho ◽  
AL Cypriano-Souza ◽  
PC Simões-Lopes

Oceanic waters are difficult to assess, and there are many gaps in knowledge regarding cetacean occurrence. To fill some of these gaps, this article provides important cetacean records obtained in the winter of 2010 during a dedicated expedition to collect visual and acoustic information in the Vitória-Trindade seamounts. We observed 19 groups of cetaceans along a 1300-km search trajectory, with six species being identified: the humpback whale (Megaptera novaeangliae, N = 9 groups), the fin whale (Balaenoptera physalus, N = 1), the Antarctic minke whale (Balaenoptera bonaerensis, N = 1), the rough-toothed dolphin (Steno bredanensis, N = 1), the bottlenose dolphin (Tursiops truncatus, N = 2), and the killer whale (Orcinus orca, N = 1). Most humpback whale groups (N = 7; 78%) were observed in the Vitória-Trindade seamounts, especially the mounts close to the Abrolhos Bank. Only one lone humpback whale was observed near Trindade Island after a search effort encompassing more than 520 km. From a total of 28 acoustic stations, humpback whale songs were only detected near the seamounts close to the Abrolhos Bank, where most groups of this species were visually detected (including a competitive group and groups with calves). The presence of humpback whales at the Trindade Island and surroundings is most likely occasional, with few sightings and low density. Finally, we observed a significant number of humpback whales along the seamounts close to the Abrolhos Bank, which may function as a breeding habitat for this species. We also added important records regarding the occurrence of cetaceans in these mounts and in the Western South Atlantic, including the endangered fin whale.


1971 ◽  
pp. 157-159
Author(s):  
T. C. Hsu ◽  
Kurt Benirschke

Author(s):  
Juan Esteves ◽  
Arnaldo Figueredo ◽  
Rodrigo Acosta ◽  
Carlos Lira ◽  
Luis Bermúdez-Villapol

The stranding of an adult male Balaenoptera physalus (Mysticeti: Balaenopteridae) in Los Cocoteros Beach in Margarita Island, Venezuela, gave the chance of studying the interactions present in it. 33 injuries were found in several points of rorqual tegument; oval or rounded in shape, like craters, from 5 to 7 cm long, 5 to 6 cm wide, and 3 to 5 cm deep. Most of them, were fresh. Wounds were attributed to the cookie cutter shark Isistius sp. (Elasmobranchii: Dalatiidae), given the remarkable correspondences. The present noteconstitutes the first known association between the cookie cutter shark and the fin whale in Venezuelan, Caribbean and western Atlantic waters.


2012 ◽  
Vol 8 (1) ◽  
pp. 20 ◽  
Author(s):  
Sandro Mazzariol ◽  
Federica Marcer ◽  
Walter Mignone ◽  
Laura Serracca ◽  
Mariella Goria ◽  
...  

1984 ◽  
Vol 62 (2) ◽  
pp. 193-198 ◽  
Author(s):  
D. J. St. Aubin ◽  
R. H. Stinson ◽  
J. R. Geraci

The structure and composition of baleen from seven species of whales was studied using tensiometry. X-ray diffraction, and elemental analysis. Baleen was found to be composed principally of amorphous and α-keratin. Hydroxyapatite (bone mineral, Ca10 (PO4)6 OH2) was present in all species. Certain elements, notably manganese, copper, boron, iron, and calcium were more highly concentrated in the fibers than in the matrix of the plate. The breaking strength of baleen plates from fin (Balaenoptera physalus), sei (B. borealis), and grey (Eschrichtius robustus) whales was comparable to that of buffalo horn, in the range of 2−9 × 106 N∙m−2. The stiffness of baleen was somewhat less than that of other keratinized tissues. Treatment with 10% (v/v) trichloroacetic acid for 8 days removed most of the calcium salts, denatured α-keratin, and made fin whale plates stronger and stiffer. Exposure to gasoline for 1.5 h or 14 days, crude oil for 8 days, or tar for 21 days resulted in loss of trace elements from baleen, and inconsistent changes in keratin organization. After tar exposure, fin whale baleen plates were stiffer and stronger. We presume that at sea, baleen would be relatively resistant to damage by spilled oil.


Author(s):  
Hasan Sajedi ◽  
Miralam Mahdi

Marine propeller always operates in the wake of a vehicle (ship, torpedo, submarine) but (due to the high computational cost of simulating vehicle and propeller simultaneously) to investigate the propeller geometric parameters, simulations are usually performed in open-water conditions. In this article, using the computational fluid dynamics method with the control volume approach, the effect of the rake angle on the propeller performance and formation of cavitation in the uniform flow (open water) and the nonuniform flow (wake flow) was investigated. In the nonuniform condition, the array of plates was used to simulate wake at upstream propeller. For uniform flow, steady solution scheme was adopted and for nonuniform flow unsteady solution scheme was adopted, and a moving mesh zone was generated around the propeller. To simulate cavitation a multiphase mixture flow, the Reynolds-averaged Navier–Stokes method was used and modeled by Schnerr Sauer's cavitation model. First, the E779a propeller model for numerical validation in the uniform flow and nonuniform flow was investigated. Numerical results were compared with the experimental result, and there was a good agreement between volume of the cavity, thrust, and torque coefficients. To study the effect of rake angle on the performance of B-series propellers, four models with different rake angles were modeled, and simulation was investigated behind the wake. The results of thrust, torque coefficients, and cavitation volume according to the flow parameters and cavitation number were presented as graphs. The results reveals that in the uniform flow, the rake angle has no significant effect on the propeller performance, but behind the wake flow, increase of rake causes to reduce the force applied to the propeller blades, cavitation volume, and pressure fluctuations on the propeller.


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