skip to Main Content

usa+1 (903) 231-3943 ge+995 (593) 675-107

Sale

Corona Virus Spread due to a Cough, CFD Simulation

$134.00 $62.00

Rated 0 out of 5
(be the first to review)

In this project the spread of the corona virus due to a cough in the open air is simulated.

This ANSYS Fluent project includes CFD simulation files and a training movie.

There are some free products to check the service quality.

To order your ANSYS Fluent project (CFD simulation and training), contact our experts via info@mr-cfd.com, online support, and WhatsApp.

Description

Corona Virus Project Description

Today, the whole world is facing one of the biggest and most fundamental human challenges called corona disease (Covid 19). The main and dangerous problem of this disease is its high contagious power from an ill to a healthy person. The main way the disease is transmitted from person to person is through viruses in the patient’s oral and nasal secretions. For this reason, doctors recommend that shake hand and hugging be severely prevented; But one of the problems is the spread of the virus of this disease through the patient’s cough and sneezing in space.

This spreads the virus particles in the open air and can infect a person at a certain distance from the patient. Therefore, one of the most up-to-date topics that researchers are constantly researching is calculating and examining the minimum appropriate distance between a sick person and a healthy person to prevent the spread and transmission of viruses when a patient coughs or sneezes called social distancing or physical distancing. Now, based on the CFD method and using ANSYS Fluent software, it is possible to simulate the release of corona virus particles from the patient’s mouth during coughing.

This model involves a human placed in a cube-shaped computational domain as open air, and the human mouth is distinguished as a source of virus transmission. To simulate this model, a discrete phase model must be used. This model allows us to study a set of discrete particles in a continuous fluid space . In this model, the wet particles of the virus secreted from the patient’s mouth are defined as a discrete phase and the airflow as a continuous phase in space.

corona virus

Project Description

Physical models of these discrete particles include two-way turbulence coupling, meaning the effect and interaction between the continuous and discrete phase by activating the interaction with continuous phase mode, Discrete phase also affects the continuous phase, stochastic collision means irregular droplets colliding with each other, coalescence means droplets merging with each other, and breakup that means the collapse of the droplets. Also, the type of discrete phase behavior will be time dependent and with a time step of 0.001 s (by activating the unsteady particle tracking mode).

By activating the discrete phase model, it is time to define the injection process, which determines the type and quality of discrete particles injected into the model. In this model, injection particles are defined as droplet; Thus, water is defined as a droplet material and water vapor is defined as an evaporating gas. The injection is performed superficially and through the inner surface of the patient’s mouth (inlet-mouth). According to this definition of injection, virus particles from human cough are physically expelled from the mouth by water droplets that are evaporating in space.

These droplets have a temperature of 310 K, a velocity of 31.85 m.s-1, and a flow rate of 0.018 kg.s-1, which are emitted in the interval of 0 s to 0.1 s. The diameters of these particles are not constant and equal to each other, and therefore, the rosin-rammler-logamethric distribution method is considered for the size of the diameters. Determine the minimum, maximum and middle diameter size, spread parameter and the number of diameters per injection. It should be noted that the droplet mode is applied when the species model is enabled.

corona virus

Project Description

In this model, the mode of species transport is activated in order to simulate the droplet and evaporation, and thus the working space of the model around the patient will have the airflow. The boundary conditions of the model are defined as ESCAPE for particles at the boundaries of the mouth and the walls around the space, means that the particles pass through these boundaries, at the boundary of the body with a REFLECTION state, means the reflection of particles that collide with this boundary, and at the boundary of the earth they have a TRAP state, meaning that particles are trapped and accumulate at this boundary.

Also, the type of boundary condition for the boundary walls of the patient’s surrounding space is defined as pressure outlet and the type of boundary condition for other boundaries is defined as the wall. The process of this simulation was performed at a time interval of 1.75 s, with a time step size of 0.1 s from the beginning of this period, the virus was spread through coughing. The following figure shows a schematic of the problem model.

corona virus

Geometry & Mesh

The present 3-D model is designed using SOLIDWORKS and Design Modeler software. The model geometry consists of a human with a in a standing position, which is located within a certain computational space containing air flow. The space around a human consists of a rectangular cube measuring 3 m * 3.5 m * 2.8 m, which represents a part of the open air around the person’s body. This free space is intended to study the distribution of wet viral particles released from the mouth.

The surface of the patient’s mouth is distinguished by an inlet-mouth boundary condition; Because this surface is assumed as the discrete phase virus release in this model. The following figure shows a view of the geometry.

corona virus

The meshing of the model has been done using ANSYS Meshing software and the mesh type is unstructured. The accuracy of the mesh is higher in areas close to the patient’s mouth than elsewhere. The element number is 584587 . The following figure shows the mesh.

corona virus

Corona Virus CFD Simulation Setting

To simulate the present model, we consider several assumptions:

  • We perform a pressure-based solver.
  • The simulation is unsteady. Because the purpose of the problem is to track the particles related to the discrete phase over time.
  • The gravity effect on the fluid is equal to -9.81 m.s-2 along the z-axis.

A summary of the defining steps of the problem and its solution is given in the following table:

Models (Covid 19)
Viscousk-epsilon
k-epsilon modelRNG
near-wall treatmentstandard wall function
Species modelSpecies transport
number of volumetric species3 (H2O,O2,N2)
Discrete phase modelOn
interactioninteraction with continuous phase
(Corona Virus)particle treatmentunsteady particle tracking
physical modelstwo-way turbulence coupling
stochastic collision
coalescence
breakup
Injectionactive
injection typedroplet
release from surfacesinlet-mouth
materialwater-liquid
evaporating speciesH2O
diameter distributionrosin-rommler-logarithmic
point propertiestemperature310 K
velocity31.85 m.s-1
total flow rate0.018 kg.s-1
EnergyOn
Boundary conditions (Covid 19)
FloorWall
wall motionstationary wall
heat flux0 W.m-2
discrete phase conditionstrap
AroundPressure outlet
gauge pressure0 Pascal
discrete phase conditionsescape
Inlet-mouthWall
wall motionstationary wall
heat flux0 W.m-2
discrete phase conditionsescape
Man bodyWall
wall motionstationary wall
heat flux0 W.m-2
discrete phase conditionsreflect
Methods (Covid 19)
Pressure-velocity couplingCoupled
pressuresecond order
momentumfirst order upwind
H2Ofirst order upwind
O2first order upwind
energyfirst order upwind
Initialization (Covid 19)
Initialization methodsHybrid

Corona Virus Results

At the end of the solution process, we obtain the particle tracking of the virus particles. This particle sequence is based on the output resistance time. We take out the animation of the virus release and its disappearance over time. Also, we obtain and present the images related to the virus particle sequence at different times. The results show the spread of the virus during the patient’s cough, which occurs in the open air over a period of 0.1 s to 1.75 s.

All files, including Geometry, Mesh, Case & Data, are available in Simulation File. By the way, Training File presents how to solve the problem and extract all desired results.

Reviews

There are no reviews yet.

Leave a customer review

Your email address will not be published. Required fields are marked *

Back To Top
×Close search
Search
Call On WhatsApp