Minor Losses: Sharp Versus Smooth Entrance — Homework

Overview

As we learned in this course, pipe fittings, valves and bends introduce minor losses which are expressed in the K-factor form. This enables the calculation of the pressure loss through the fitting for a particular fluid flowing at a specified velocity. These local loss coefficients are often published by manufacturers so that engineers designing flow systems can take into consideration minor losses and scope an appropriate pumping capacity. In this example, we will calculate and compare the K-factor associated with two types of entrance losses — a sharp entrance and a smooth entrance.

Objectives

In this example, you will learn how to set up two axisymmetric pipe entrance flow problems with sharp and smooth entrances in Ansys Fluent. You will post-process the results to visualize how the entrance shape affects the flow field. Lastly, you will calculate the K-factors by measuring the associated pressure losses through the system.

Setup

Download the Mesh file required for setting up the simulation and associated Case & Data files here. Follow the instructions below to set up this simulation in Ansys Fluent starting with the Mesh file. In case you face any issues setting up or running the simulation, refer to the corresponding initial and final Case and Data files.

Alternate video link.

Results & Discussion

Let’s now take a look at how the K-factors obtained from simulations compare with each other.