What is the difference between hydraulic diameter and equivalent diameter?

The hydraulic diameter is not the same as the equivalent diameter. The equivalent diameter is the diameter of a circular duct or pipe that gives the same pressure loss as a rectangular duct or pipe.

What is hydraulic diameter in fluid mechanics?

Introduction. The hydraulic diameter (aka hydraulic mean diameter) is used for a fluid flowing in a pipe, duct or other conduit of any shape. This uses the perimeter and the area of the conduit to provide the diameter of a pipe which has proportions such that conservation of momentum is maintained.

What is the characteristic length in fluid mechanics?

In simple terms, a characteristic length is THE MOST important length scale in a fluid flow. For example: (1) In a VERY LONG pipe or channel flow, the characteristic length is diameter or channel width – By very long, I meant the velocity becomes independent of the pipe length.

What do you mean by hydraulic diameter and its impact on heat exchanger?

Hydraulic diameter – dh – is the “characteristic length” used to calculate the dimensionless Reynolds Number and Nu number. Therefore it is vital for evalution of different types of heat exchangers. In literature there are many different formulas which lead to different results (sometimes 5x difference).

What is meant by characteristic length?

In physics, a characteristic length is an important dimension that defines the scale of a physical system. In computational mechanics, a characteristic length is defined to force localization of a stress softening constitutive equation. The length is associated with an integration point.

What is characteristic length in heat transfer?

For your problem (convective heat transport of an object submerged in a liquid at elevated temperature) the characteristic length is the vertical size of the object. This is because the convection will take place in the vertical direction (cold water flowing down, hot water rising).

What is equivalent diameter in fluid mechanics?

The equivalent diameter is the diameter of a circular duct or pipe that for equal flow gives the same pressure loss or resistance as an equivalent rectangular duct or pipe.

What is hydraulic equivalent section?

Two section of different shapes is said to be hydraulically equivalent if they carry same discharge while running full on the same grade and are of the same material.

How do you find the equivalent diameter?

The equivalent diameter is defined as the diameter of a circle with an equal aggregate sectional area, which is calculated by d = 2 Area / π .

How do you determine characteristic length?

The characteristic length is commonly defined as the volume of the body divided by the surface area of the body, i.e. Highly active question.

What are the characteristics of the dimension?

A dimension is a structure that categorizes data to enable users to answer business questions. Commonly used dimensions are Customers, Products, and Time. A dimension’s structure is organized hierarchically based on parent-child relationships.

Is the hydraulic diameter the same as the equivalent diameter?

The hydraulic diameter is not the same as the equivalent diameter. The equivalent diameter is the diameter of a circular duct or pipe that gives the same pressure loss as a rectangular duct or pipe.

What is the hydraulic diameter of a duct?

The hydraulic diameter transforms non-circular ducts into pipes of equivalent diameter. Using this term, one can calculate many things in the same way as for a round tube. In this equation A is the cross-sectional area, and P is the wetted perimeter of the cross-section.

What is the difference between hydraulic diameter and velocity in Reynolds?

Note that the velocity in the Reynolds equation is based on actual cross section area of duct or pipe. The hydraulic diameter is used the Darcy-Weisbach equation to calculate pressure loss in ducts or pipes. Note! – the hydraulic diameter is not the same as the geometrical equivalent diameter of non-circular ducts or pipes.

How to calculate hydhydraulic diameter?

Hydraulic diameter can be calculated with the generic equation dh = 4 A / p (1)