What You Can Model with the Heat Transfer Module

Conduction, Convection, and Radiation Analyses

The Heat Transfer Module can be used to study the three types of heat transfer in detail, expanding the analyses that are possible with the core COMSOL Multiphysics® simulation platform become aruba certified design expert.

Conduction

To describe conduction that occurs in any material, you can define the thermal conductivity as isotropic or anisotropic, and it may be constant or a function of temperature (or any other model variable).

Convection

Account for the motion of fluids in heat transfer simulations. You can use features for modeling pressure work; viscous dissipation; as well as forced and free (or natural) convection. Natural convection is automatically modeled when the gravity option is selected in the Single-Phase Flow interface.

Radiation

The Heat Transfer Module enables you to model surface-to-surface radiation using the radiosity method as well as radiation in participating media using the Rosseland approximation, P1 approximation or discrete ordinate method (DOM). The P1 approximation and DOM are also available for radiation in absorbing and scattering media, to model light diffusion in a nonemitting medium, for example. You can also model a radiative beam in absorbing media radiation using the Beer-Lambert law and couple the effect with other forms of heat transfer.

Temperature and velocity in an LED bulb

What You Can Model with the Heat Transfer Module

Whether heat transfer is the primary area of focus or part of a larger, complex analysis, you most likely need to examine multiple physical effects at once. With the multiphysics modeling capabilities of the COMSOL® software, you are able to perform complete and thorough analyses in one simulation environment, following a consistent workflow across physics. This intuitive approach to modeling and simulation can be used to account for heat transfer and all of the physical phenomena involved in your application.

Browse the following applications to see a small sample of what you can analyze and simulate with COMSOL Multiphysics® and the Heat Transfer Module.

Wi-Fi signal strength can be increased with aluminum foil

Scientists have discovered a simple and inexpensive way to increase the power of Wi-Fi signals inside our homes and this is based on the use of aluminum foil.

The researchers say that using a reflective screen made of aluminum foil, as a "virtual wall" positioned behind the Wi-Fi router, you can control the direction of propagation of wireless signals inside homes. This way we can improve the power of the wireless signal in a certain area of ​​our house.

"With this unique solution, we address a number of challenges affecting users of wireless technology."

"We have increased the power of wireless signals and made Wi-Fi connections safer," said researcher Xia Zhou of Dartmouth College, Hannover, New Hampshire.

Inspired by a simple method that would have succeeded in amplifying the wireless signal using a dose of beer, the researchers set out to study whether a similar solution could be used to optimally direct the wireless signal from the router dark fiber network.

Although there is some evidence that the use of an aluminum beer can, under certain conditions, can increase the intensity of wireless signals, this method involves making a curved aluminum panel as a reflector.

If we take into account the varied configuration of our homes, it is obvious that the solution of the location of such a reflector is not very scientific, because it does not offer an exact control over the place where the aluminum reflector directs the wireless signal.

To improve this solution, Zhou's team developed what is called WiPrint , a system that scans the interior or floor plan of your home to identify places where the Wi-Fi signal can be amplified, as well as areas where we don't need a signal. powerful wireless.

Based on this input data, the WiPrint algorithm can calculate the optimal shape of the signal reflector to be placed next to the Wi-Fi router. Subsequently, the reflector can be 3D printed in plastic and covered with aluminum foil.

The whole process of making the signal reflector takes about 23 minutes, and the only costs involved are to obtain the printed 3D frame.

"With an approximate investment of only $ 35 and the indication of wireless coverage requirements, we can make a custom reflector whose performance can be even higher than that of antennas that cost thousands of dollars," said Zhou.

The reflector made by the research team managed in tests to amplify the wireless signal by up to 55.1% in the areas where it was desired to increase its power and also managed to reduce the intensity of the wireless signal by up to 63.3% in areas where this was desired.

Aluminum foil signal reflector to increase Wi-Fi signal strength

Most of us will probably not be interested in lowering the power of the Wi-Fi signal. However, it is good to keep in mind that a high-intensity wireless signal that reaches outside our home can help malicious hackers. to take control of the wireless network we use in our home, although this risk is probably quite low.

Even if we do not have access to the researchers' algorithm for calculating the optimal shape of Wi-Fi reflectors based on the floor plan, nothing stops us from trying different forms of reflector to see if we can increase the signal coverage of the wireless network we use.

You only need to know that wireless signals must comply with certain technical regulations and, consequently, their modification, outside the permitted range, is prohibited.

"I can't really advise people to use aluminum foil or any other kind of reflector, mainly because of the regulations."

"In the US, FCC regulations set the power of wireless signals. Thus, the maximum power level of wireless routers is limited to a certain value ", said Eric Siu, Linksys product development director, who was not involved in this research.

Key features of F5 solutions

F5 Networks Careers

The hardware is designed specifically for the purpose of handling traffic.

Full-proxy architecture.

The ability to organize a universal system on a single platform.

The ability to divide resources into independent virtual devices within one physical one.

Communication capabilities: a large community of developers and users.

Tasks that F5 technologies will help solve

Resiliency and high availability of mission-critical applications.

Protection of web applications from DDoS attacks, Web Application Firewall.

Disaster recovery of data center solutions.

Consolidation of data centers, applications, data.

Optimal load balancing of applications.

Remote access to applications and / or network.

Implementation of complex application access schemes: BYOD, SSO.

Replacement of well-known EoS products: Cisco ACE and Microsoft TMG.

Refinement of the VDI architecture of VMware Horizon.

Formation of cloud infrastructure and applications (IaaS, SaaS).

Ready-to-use solutions for launching Microsoft, Oracle, HP, IBM, VMware, etc.

Ensuring PCI DSS Compliance.

Types of system administrators

System administrators can have a narrow focus and general (so-called generalists). System administrators with a general specialization are versed in various issues related to PC maintenance, and such specialists are most in demand in non-IT companies. It is more difficult for sysadmins with a narrow specialization to find a job, however, such specialists can solve the most complex problems and may be in demand in IT companies.

Types and types of system administrators: linux system

Web server administrator (in fact, this is the minimum knowledge of how to configure Apach, Nginx or IIS) 

Network administrator (more biased in networking - working with routers, VPN settings, etc.)

Network Security Administrator (anti-intrusion bias, running scanners to detect vulnerabilities, installing updates, etc.)

Administrator of mail servers (specializes in maintaining the health of mail servers, protecting users from unwanted emails, backups, working with quotas, etc.)

Additionally:

Database administrator (or DBA - in fact, has nothing to do with sysadmins and is exclusively engaged in tuning and working with a database, for example, Oracle)

Online sysadmin courses (beginners and advanced) at LinuxTrainingCenter

For sysadmins, the Linux Training Center has prepared an excellent course on learning Linux. The course "training for system administrators " includes:

After our course, you will gain practical skills of Linux system administrators at a level sufficient to perform all basic system administrator tasks (including practice in installing / configuring / administering Linux servers, setting up a network, configuring a Web server, etc.)