Mechanical Engineering Training Package, Advanced Users, Part 2, 10 Exercises

Description

Mechanical Engineering – ANSYS Fluent CFD Simulation Training Package, Practical Exercises for ADVANCED Users (Part 2)

There are 10 practical exercises in this training package by ANSYS Fluent software for Mechanical Engineers. This package presents how to simulate different mechanical devices for all ADVANCED users.

Wet Steam

Problem number 1 simulates the process of condensation inside a steam ejector using WET STEAM. When the Wet Steam multiphase model is used, two sets of transport equations are solved: the mass fraction of the condensed liquid phase and the number or concentration of droplets per unit volume.

Cavitation

Problem number 2 simulates the cavitation inside a radial flow pump. This pump is of the centrifugal pump (radial flow) type; In this way, the desired fluid enters it parallel to the central axis and exits it radially or perpendicular to the inlet path. In project number 3, the fluid flow of water and the cavitation around an inducer inside a pipe is simulated. The cavitation phenomenon is one of the phenomena that vapor bubbles are formed in the part of the fluid whose pressure is low. The phenomenon of cavitation can cause many problems, including corrosion.

Heat Pipe

In study number 4, the heat pipe problem was simulated. The project was analyzed using the multiphase VOF model and activating the mass transfer of evaporation and condensation. A hot wall with a temperature of 400 K and a cold surface with a temperature of 300 K was assumed.

Dryer

For simulation number 5, we use two types of continuous and discrete phases. In fact, the hot airflow, which is responsible for evaporating the moisture contained in the solution, enters the spray dryer chamber as a continuous phase and flows into the chamber (Eulerian). While a solution containing water and solid particles (Lagrangian) injects into the chamber as a discrete phase. In fact, the main purpose of this simulation is to investigate the behavior of particles that flow as a discrete phase in a continuous flow. In project number 6, which has been done by CFD numerical simulation method, a spray drying chamber is simulated by the two-way DPM and Species Transport model. The particle diameter is 1 mm, and the flow moves at a speed of 1 m/s. Also, the gravity effect is equivalent to -9.81 m.s-1. In project number 7, a rice drying device has simulated using the Two-way Discrete Phase Model (DPM) & Species Transport Model, and then the results were investigated. Hot air enters the drying device, and then 120000 rice grains with 10% moisture are injected randomly for 6 seconds. The evaporation process continues for 9 seconds after complete injection.

Air Freshener Spray

Practical exercise number 8 investigates the spraying of Air Fresheners in the restroom by the 2-way DPM method. According to this definition of injection, fragrance particles are physically expelled from the device by water droplets that evaporate in space. These droplets have a temperature of 310 K, a velocity of 50m.s, and a mass flow of 0.018 kg.s-1, which are emitted at intervals of 0s to 0.1s.

Paper Numerical Validation (Mechanical Engineering)

Problem number 9 simulates fuel injection through an injector into a chamber. This simulation is based on the information in the article “Spray-induced air motion in single and twin ultra-high injection diesel sprays” and its results are compared and validated with the results in the article. The fuel used in this model is diesel and its properties include density equal to 830 kg.m-3, specific heat capacity equal to 1680 j.kg-1.K-1, droplet surface strain equal to 0.0255 nm -1 and the viscosity is equal to 0.0027888 kg.m-1.s-1. Finally, practical exercise number 10 simulates the water vapor flow inside a steam ejector. This numerical simulation is based on the reference paper “CFD simulation on the effect of primary nozzle geometries for a steam ejector in refrigeration cycle” and the results of the present numerical work are compared and validated with the results in the reference article. An ejector is a mechanical device that uses an actuator fluid to suck a secondary material (gas, liquid, or solid particles), and finally, the actuator fluid and the suction substance are mixed together and exit from the system.