Bluff body hydrodynamics twentyfirst symposium on naval. This book covers a small part of the numerous cases of stationary and non stationary aerodynamics. Perspectives on bluff body aerodynamics journal of wind engineering and industrial aerodynamics, vol. This workshop will help you understand how aerodynamics affect free fall and how advanced wingsuit technology can take advantage of this. The ahmed body is used as a reference model for fundamental studies of cartype bluff body aerodynamics, in particular focused on the influence of the rear slant angle on the drag coefficient.
Different response modes and flow phenomena exist depending on the flow characteristics, the body geometry and the structural properties like stiffness and damping. The problem of bluffbody drag at high reynolds number is one of the oldest unsettled ones in. It was found that, while behind the upstream body, the wing experienced a decrease in its downforce values, with the amount of downforce. The aerodynamic characteristics of bluff bodies differ substantially from streamlined bodies, and an understanding of bluff body aerodynamics is essential to make progress in understanding wind engineering. Pdf bluff body aerodynamics and wake control demetri. Fluid flow past bluff bodies such as circle or square cylinder is of great concern in previously published literature. Aerodynamics of the flying snake chrysopelea paradisi how. Free shear layers, base pressure and bluffbody drag dtic. About 60 % of the aerodynamic drag forces of a passenger vehicle are related to.
High resolution schemes for bluff body aerodynamics. High resolution schemes in bluff body aerodynamics. These vortices are shed from the surfaces of the body and are then carried downstream. Aerodynamics and dynamics of bluff bodies in presence of. Bluff body article about bluff body by the free dictionary. A streamlined body, like an aircraft wing or a race car or an aircraft itself. Some effects of free stream turbulence on the flow past a cantilevered circular cylinder y. While the measurement principle of the swirlmaster is based on concentric swirls that create pressure fluctuations in the medium, the vortexmaster works according to the karman vortex principle with turbulences generated by a bluff body. Journal of wind engineering and industrial aerodynamics.
Help us write another book on this subject and reach those readers. In aerodynamics, a bluff body is one which has a length in the. Aerodynamics, from a modern point of view, is a branch of physics that study physical laws and their applications, regarding the displacement of a body into a fluid, such concept could be applied to any body moving in a fluid at rest or any fluid moving around a body at rest. In threedimensional bluff body flows, shear layer behaviour has a primary influence on the surface pressure distributions and, therefore, the integrated forces and moments. Pdf bluff body aerodynamics and wake control researchgate.
Numerical characterization of threedimensional bluff body. The first covers atmospheric flows, extreme wind speeds, and bluff body aerodynamics. Bluffbody aerodynamics and turbulence sciencedirect. Status of pans for bluff body aerodynamics of engineering. An alternate way is to utilize computational fluids dynamics. Unstable wake dynamics of rectangular flatbacked bluff. Pdf experimental aerodynamic study of a cartype bluff body. Aerodynamic drag of bluff body shapes characteristic of. Compared with conventional airfoils, bluff bodies exhibit considerably different aerodynamic performance, characterized by aerodynamics of the flying snake chrysopelea paradisi. Lilleyon the turbulent mixing of compressible free shear layers. Aerodynamic drag of bluff body shapes characteristic of hatchback cars 780267 the flow around a bluff body with a slanted rear surface is influenced very dramatically by changing the angle of the rear surface slant and at some slant angles an excessively high drag is generated. The typical terminology and designation of these forces and moments are given in. This work focuses on the aerodynamics of the rearend and underbody of bluff bodies in general, but also applied to passenger cars.
Fluid flow is defined by means of various characteristics like. Key fields addressed are urban physics, wind engineering and sports aerodynamics. We can understand this by returning to the flow of a nonviscous fluid around a cylinder. This course explains basic aspects of bluff body aerodynamics, wind tunnel testing and computational fluid dynamics cfd simulations with application to sports and building aerodynamics. In most situations it is inevitable that the boundary layer becomes detached from a solid body. Moving surface boundarylayer control msbc was applied to several two dimensional bluff bodies using a high speed rotating cylinder as a momentum injecting device. View notes chapter 5 bluff body aerodynamics from ces 5587 at florida international university. The interaction between a fluid flow and an embedded elastic bluff body is extremely complex. On the wake and drag of bluff bodies journal of the.
Unstructured grids pdf lecture 49 solution convergence pdf. Request pdf bluff body aerodynamics bluff body aerodynamics of interest in structural engineering applications is associated with atmospheric flows, which. In the wake the flow is turbulent but a distinguished pattern of vortices can usually be seen. Conceptual overview of laminar and turbulent flows past smooth and rough circular cylinders m. Aerodynamic stabilization of several suspension bridges recently built in china is introduced hereafter, and followed by aerodynamic feasibility study of a 5000mspan suspension bridge. Particle methods in bluff body aerodynamics rasmussen, johannes tophoj publication date. Experimental aerodynamic study of a cartype bluff body. While much of our understanding of road vehicle aerodynamics has developed. The objectives of the present work are to obtain reliable drag coefficient comparable to the literature and to explain, based on the nature of the flow, its variation when changing the rear slant angle. Clearly bluff body aerodynamics and bluff body hydrodynamics are closely related but. Aerodynamics of free fall ace climatic wind tunnel. Bluff body aerodynamics and application how is bluff. The aerodynamic characteristics of bluff bodies differ substantially from streamlined bodies, and an understanding of bluff body aerodynamics is essential to make progress in understanding wind.
Both series have a piezo sensor with multiple elements to register the measured signals and additionally the pipe vibrations with which the measurement signal. Aerodynamics of a wing in ground effect in generic racing. Study materials section contains the additional notes to be used in the course. Experimental aerodynamic study of a cartype bluff body article pdf available in experiments in fluids 505. Bluff body aerodynamics and application international colloquium bbaa.
Bluff body aerodynamics and applications sciencedirect. Apply this understanding to improve flight performance and stability predictions. Bluffbody aerodynamics influence on transport and diffusion r. The application range from flows around generic bluff bodies such as a finite cylinder to flows around simplified road vehicles, trains and landing gears. The results were then compared with baseline data that were obtained without the presence of the bluff body.
Jenkins2 1centre for fluid mechanics and computational science cran. Perspectives on bluff body aerodynamics caltechauthors. Bluff body, viscous flow characteristics immersed bodies in general, a body immersed in a flow will experience both externally applied forces and moments as a result of the flow about its external surfaces. Abstract this paper explores a number of aspects of bluff body research that. The parameter characterizing the effects of compressibility is then the mach number. Bluff body aerodynamics and wake control, applied aerodynamics, jorge colman lerner and ulfilas boldes, intechopen, doi. As both blunt and bluff represent the same idea, that of a body that causes high drag. Readers are suggested to study bluff body aerodynamics and wake control by efstathios konstantinidis and demetri bouris 15 for further and detail study of flow instabilities and vortex.
Bluff body aerodynamics and wake control intechopen. For air at the pressure of one atmosphere and t 15c standard conditions, we have a. Lecture 44 implications of linearized supersonic flow on airfoil lift and drag pdf lecture 45 oblique shock waves pdf lecture 46 prandtlmeyer expansion waves pdf lecture 47 computational methods for the euler equations pdf lecture 48 structured vs. Westthe effects of wake splitter plates on bluffbody flow in the range 104. This is due to a relatively square shape, with a length height ratio of approximately three, and a truncated rearend that generates a wake. Modern structural design for wind, 4 th edition is organized in four sections.
The base pressure and drag are then determined from freestreamline theory. Basic bluffbody aerodynamics relationship between force coefficients in two axes systems. Bluff body aerodynamics and application how is bluff body aerodynamics and application abbreviated. This boundary layer separation results in a large increase in the drag on the body.
Threedimensional bluff body aerodynamics are pertinent across a broad range of engineering disciplines. This being the main objective, optimisation of body aerodynamics i. When a bluff body is embedded in a fluid flow it may cause a wake forming behind the body. Journal of wind engineering and industrial aerodynamics, 49. A selection of papers presented at the international colloquium on bluff body aerodynamics and its app m. Shedding is erratic and multimodal, but strouhal numbers are typically in the range 0. The effects of nonlinearity and unsteadiness on bluffbody aerodynamics are evaluated by comparing aerodynamic responses derived from different analytical models. Journal of wind engineering and industrial aerodynamics, 14 1983 479483 479 elsevier science publishers b. Perspectives on bluff body aerodynamics sciencedirect. F x d cos o l sin o f y d sin o l cos o basic bluffbody aerodynamics dependence of pressureforce coefficients on other nondimensional groups. With more than 2,400 courses available, ocw is delivering on the promise of open sharing of knowledge. A passenger car is a bluff body aerodynamically, with pressure forces at the rear that dominate the aerodynamic drag. Bluff body aerodynamics and application listed as bbaa.
1296 1172 631 724 1361 593 143 1039 632 1443 403 108 628 1534 447 255 542 684 1309 1182 1441 1099 1145 529 975 1151 1562 362 1375 1534 119 1524 1259 1361 1238 631 1305 1011 1144 710 1069 256 1260 912 161