Search results
Results From The WOW.Com Content Network
is the Reynolds number with the cylinder diameter as its characteristic length; Pr {\displaystyle \Pr } is the Prandtl number . The Churchill–Bernstein equation is valid for a wide range of Reynolds numbers and Prandtl numbers, as long as the product of the two is greater than or equal to 0.2, as defined above.
Illustration of a cylinder and the planification of its lateral surface. The lateral surface of a right cylinder is the meeting of the generatrices. [3] It can be obtained by the product between the length of the circumference of the base and the height of the cylinder. Therefore, the lateral surface area is given by: =. [2]
The bare term cylinder often refers to a solid cylinder with circular ends perpendicular to the axis, that is, a right circular cylinder, as shown in the figure. The cylindrical surface without the ends is called an open cylinder. The formulae for the surface area and the volume of a right circular cylinder have been known from early antiquity.
The following is a list of centroids of various two-dimensional and three-dimensional objects. The centroid of an object in -dimensional space is the intersection of all hyperplanes that divide into two parts of equal moment about the hyperplane.
The hydraulic diameter, D H, is a commonly used term when handling flow in non-circular tubes and channels. Using this term, one can calculate many things in the same way as for a round tube. When the cross-section is uniform along the tube or channel length, it is defined as [1] [2] =, where
For instance for a circular cylinder of diameter D in oscillatory flow, the reference area per unit cylinder length is = and the cylinder volume per unit cylinder length is =. As a result, () is the total force per unit cylinder length:
Sometimes different reference areas are given for the same object in which case a drag coefficient corresponding to each of these different areas must be given. For sharp-cornered bluff bodies , like square cylinders and plates held transverse to the flow direction, this equation is applicable with the drag coefficient as a constant value when ...
The radius is r=0.200 m = 200 mm, or a diameter of 400 mm. If one adds a factor of safety of 5 and re-calculates the radius with the admissible stress equal to the τ adm =τ yield /5 the result is a radius of 0.343 m, or a diameter of 690 mm, the approximate size of a turboset shaft in a nuclear power plant.