streamlining


Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.

Streamlining

The contouring of a body to reduce its resistance (drag) to motion through a fluid.

For fluids with relatively low viscosity such as water and air, effects of viscous friction are confined to a thin layer of fluid on the surface termed the boundary layer. Under the influence of an increasing pressure, the flow within the boundary layer tends to reverse and flow in an upstream direction. Viscosity tends to cause the flow to separate from the body surface with consequent formation of a region of swirling or eddy flow (termed the body wake; illus. a). This eddy formation leads to a reduction in the downstream pressure on the body and hence gives rise to a force opposite to the body motion, known as pressure drag. See Wake flow

Flow about bodies in uniform subsonic flowenlarge picture
Flow about bodies in uniform subsonic flow

In general, streamlining in subsonic flow involves the contouring of the body in such a manner that the wake is reduced and hence the pressure drag is reduced. The contouring should provide for gradual deceleration to avoid flow separation, that is, reduced adverse pressure gradients. These considerations lead to the following general rules for subsonic streamlining: The forward portion of the body should be well rounded, and the body should curve back gradually from the forward section to a tapering aftersection with the avoidance of sharp corners along the body surface. These conditions are well illustrated by teardrop shapes (illus. b).

At supersonic speeds the airflow can accommodate sudden changes in direction by being compressed or expanded. Where this change in direction occurs at the nose of the body, a compression wave is created, the strength of which depends upon the magnitude of the change in flow direction. Lowering the body-induced flow angle weakens this compression shock wave. When the flow changes direction again at the midpoint of the body, the air will expand to follow the shape of the body. This change in direction creates expansion waves. At the tail of the body the direction changes again, creating another compression or shock wave. At each of these shock waves, changes in pressure, density, and velocity occur, and in this process energy is lost. This loss results in a retarding force known as wave drag. See Shock wave

Bodies which are streamlined for supersonic speeds are characterized by a sharp nose and small flow deflection angles. Because the intensity of the shock wave and the drag level is dependent upon the magnitude of the change in flow direction, the width or thickness of the body should be minimal. See Boundary-layer flow

streamlining

[′strēm‚līn·iŋ]
(design engineering)
The contouring of a body to reduce its resistance to motion through a fluid.
References in periodicals archive ?
In our view, the starting point for streamlining Form 1120 should be for the IRS to identify its minimum requirements in respect of tax return information and formatting.
Streamlining with legal breaststroke start: Use legal breaststroke start and stroke (25-50 yards), two-hand touch and legal turn.
Thus far, the following specific actions have resulted from streamlining activities:
Streamlining with flutter kick, using right-arm touch swimming and breathing on the right side (25-50 yards).
Against this complex backdrop of fundamental change, streamlining has emerged in the public program of vocational rehabilitation as one response to a complex set of circumstances.
Within 1 year of the first 2-day retreat initiating the streamlining process, Vermont had articulated a vision for the future, had designed strategic goals, embarked on a process of regular monitoring of agency progress, retained a professional systems change consultant, developed plans for new configurations for a streamlined agency structure, and began experimenting with new strategies to expand consumer choice.
To fully understand the implementation of the streamlining agenda, it will be useful to review the actual agreement.
Key issues to be addressed during the Operational Support Systems for IP Networks and Services -- Streamlining the OSS/BSS for Optimal Service Development over IP Infrastructures conference will include: a) Real, attainable solutions for OSS/BSS integration to support the "Triple-Play", b) Management of fixed/mobile networks, MVNO, Wi-Fi and preparing for WiMax, c) Dealing with system migration, customer data management and integration, and data modelling and mapping, d) Strategies for improved provisioning, testing billing and customer care, e) Discussion on the Next Generation OSS, the standards landscape, and the rise of the Next-Generation CIO.
Rocksoft delivers the data streamlining and integrity assurance technologies that power the information management infrastructure by eliminating data redundancy, reducing overhead and improving performance in data access and storage.
VHB), the environmental engineering, and planning, firm, created and led the streamlining process, which has taken less than two years to complete when normally it can last up to four years to compete a runway EIS.
Claims Recovery Solution Expected to Increase Claim Payments and Related Revenue, While Streamlining Operations
We've eliminated installation and maintenance headaches associated with our previous thick client solution and boosted productivity by streamlining internal processes and reducing data duplication.

Full browser ?