Analyze Thermal Effects with the Heat Transfer Module

Heat Transfer Modeling Software for Advanced Simulation

Analyze heat transfer by conduction, convection, and radiation with the Heat Transfer Module, an add-on product to the COMSOL Multiphysics® platform. The Heat Transfer Module includes a comprehensive set of features for investigating thermal designs and effects of heat loads. You can model the temperature fields and heat fluxes throughout devices, components, and buildings. To examine the real-world behavior of a system or design virtually, easily couple multiple physical effects in one simulation with the multiphysics modeling capabilities included in the software aruba certified design expert (acdx).

Specialized Features for Heat Transfer Analyses

Conjugate Heat Transfer and Nonisothermal Flow

The Heat Transfer Module contains features for modeling conjugate heat transfer and nonisothermal flow effects. These capabilities can be used to model heat exchangers, electronics cooling, and energy savings, to name a few examples.

Both laminar and turbulent flow are supported and can be modeled with natural and forced convection. It is possible to account for the influence of pressure work and viscous dissipation on temperature distribution. Turbulence can be modeled using Reynolds-averaged Navier-Stokes (RANS) models such as the k-ε, low-Reynolds k-ε, algebraic yPlus, or LVEL turbulence models. The realizable k-ε, k-ω, shear stress transport (SST), v2-f, and Spalart-Allmaras turbulence models are available when combined with the CFD Module.

The temperature transition at the fluid-solid interface is automatically handled using continuity, wall functions, or automatic wall treatment, depending on the flow model. Natural convection can be easily accounted for by activating the Gravity feature.

A nonisothermal flow modeling example of using COMSOL Multiphysics and the Heat Transfer Module.

Thin Layers and Shells

For modeling heat transfer in thin layers, the Heat Transfer Module provides specialized layer models and layered material technology to easily define complex configurations and investigate heat transfer in layers that are geometrically much smaller than the rest of a model. This functionality is available for thin layers, shells, thin films, and fractures.

For individual layers, the thermally thin layer model is used for highly conductive materials in situations where the layer contribution to the heat transfer is primarily in its tangential directions and where the temperature difference between the layer sides is negligible. Conversely, the thermally thick layer model can represent poorly conducting materials that act as a thermal resistance in the shell's perpendicular direction. This model computes the temperature difference between the two layer sides. Finally, the general model provides a highly accurate and universal model, as it embeds the complete heat equations. Layered material features support similar heat loads to the regular domain model. In particular, heat sources and sinks can be defined on layers or at layer interfaces, and heat flux and surface-to-surface radiation can be defined on both sides of the shells.

When employing the layered material technology, there are preprocessing tools for detailed layered material definition, load/save of layered structure configurations from/to a file, and layer preview features. Additionally, tools are included to visualize results in thin, layered structures as if they were originally modeled as 3D solids; specifically, surface plots, slice plots, and through thickness plot are supported. The layered material functionality is included in the AC/DC Module and the Structural Mechanics Module, making it possible to include multiphysics couplings like electromagnetic heating or thermal expansion on layered materials.

Surface-to-Surface Radiation

The Heat Transfer Module uses the radiosity method to model surface-to-surface radiation on diffuse surfaces, mixed diffuse-specular surfaces, and semitransparent layers. These are available in 2D and 3D geometries, and in 2D axisymmetric geometries when modeling diffuse surfaces. The surface and ambient properties may depend on temperature, radiation wavelength, or any other quantity in the model. Transparency properties can also be defined per spectral band (and an arbitrary number of spectral bands is supported).

Predefined settings are available for solar and ambient radiation, where the surface absorptivity for short wavelengths (the solar spectral band) may differ from the surface emissivity for the longer wavelengths (the ambient spectral band). In addition, the sun radiation direction can be defined from the geographical position and time.

The view factors are computed using the hemicube, the ray-shooting, or direct integration area method. For computationally effective simulations, it is possible to define planes or sectors of symmetry. When combined with a moving frame, the surface-to-surface radiation interface automatically updates the view factors as the geometrical configuration deforms.

Will 5G replace cable broadband networks?

Millions of people in developed countries still do not have access to broadband networks despite efforts in recent years and huge sums of money spent on connecting isolated communities.

In general, ways have been sought to expand and modernize cable networks so that everyone has access to the Internet .

With fifth-generation ( 5G ) mobile technology , which now offers considerably higher data transfer speeds than the 4G network, will we be able to give up cables altogether one day?

A 5G network supports data transfer speeds of up to 10 Gbps, has low latency or delay, and ensures the connection of up to one million electronic devices per square kilometer.

5G mobile technology allows you to download a regular high definition (HD) movie in less than 40 seconds, as opposed to more than 7 minutes via 4G mobile technology.

In fact, through 5G we can simultaneously transmit several HD videos, we can make 3D phone calls with hologram, we can access virtual reality applications, and driverless cars (autonomous) will be able to communicate with each other and the traffic infrastructure.

Unfortunately, 4G devices are not compatible with these 5G networks and to access them we need a 5G phone with a higher processing power, with a larger memory capacity (12 GB or more), but also other things like 3D holographic projectors if we want to use these features.

To access 5G networks from home we only need a 5G router.

Of course, the big challenge in replacing cable broadband networks with 5G networks is to create 5G infrastructure.

For example, UK broadband networks, which provide data transfer speeds of 24 Mbps or higher, already cover 96.4% of Internet addresses , while 5G networks are only available in major cities such as London. , Birmingham, Manchester, etc.

In order for cable data transfer speeds to be comparable to those offered by 5G, each home should be connected to the Internet with its own fiber optics.

Instead, the expansion of the 5G network requires the installation of several transmitters, connected to the fiber optic network, which can be easily accessed by a large number of users.

For this reason, it is difficult to compare the costs of each option, as both involve different infrastructure solutions.

5G Internet connection in rural areas

Connecting to the Internet for remote communities may be easier with 5G than with fiber optics. Credit: Theeraphong / Shutterstock

But providing 5G infrastructure is not everything. To compete with cable broadband providers or to replace the cable network, 5G networks must support similar data transfer speeds.

We must keep in mind that the actual speed of data transfer in mobile networks is lower than the theoretical speed.

So, although 5G theoretically supports data transfer speeds of up to 10 Gbps, the actual transfer speed in these networks can be up to 200 Mbps.

Although this speed may be sufficient for those who access the Internet only for online browsing, it may not be sufficient for users who stream multiple videos at the same time or for high-speed online gaming enthusiasts.

Another challenge for 5G mobile networks is to ensure reliable customer service, as the signals from these networks can be affected by several factors, such as the distance to the transmitter or obstacles and interference with other devices.

Improved technology: Dark Fiber

5G mobile technology providers are developing ways to overcome this problem. For example, the “massive MIMO” technology of 5G systems uses up to 96 antennas to create multiple data connections, simultaneously, between electronic devices.

Edge Computing technology (Nt An open, distributed IT architecture, characterized by decentralized data processing) involves the use of 5G towers that will process and store data without using cloud data centers, located many kilometers away .

All these features make 5G the most promising candidate to replace cable broadband networks.

Another, more difficult obstacle to developing a complete 5G network at the national level could be people's concern that this technology can be harmful to health. Even if there is no evidence of the negative health effects of 5G technology, convincing people that this technology is safe can be a challenge.

As a result, complete replacement of cable-based broadband networks with 5G networks may not be possible.

In this case, Internet users in large cities or companies may prefer cable broadband networks that are reliable, offer high transfer speeds, and are secure.

Instead, users in certain remote or rural areas will use 5G technology, as connecting to the Internet is easier than through a fiber optic network.

Always available apps with F5 Networks solutions

The most important challenge for IT departments is to provide guaranteed and secure access to business applications. Softline offers F5 Networks products designed to solve this problem.

Scope of application f5 certification

For over 20 years since its inception, F5 Networks has been developing solutions for smart application load balancing. Gartner reports its software as the leader in the Application Delivery category, which, in addition to balancing solutions, includes a variety of tools and technologies to ensure high availability, security and application performance.

F5 Networks solutions are designed for on-premises, distributed, cloud or hybrid infrastructures where mission-critical services are under heavy load, server counts and privacy requirements are high. These can be corporate business applications in the data center, the back-end of the bank-client system, social networks, online stores, government service portals and other web services.

More than 16,000 organizations worldwide use F5 Networks products, including 49 Fortune 50 companies.

Softline recommends the following F5 Networks solutions

F5 BIG-IP is the company's flagship solution. It is a hardware application delivery controller that is housed in a server rack. Has a set of software modules that work on a common platform. The client can independently choose the composition of the modules, depending on the licensing scheme.

F5 BIG-IP makes it possible to distribute the load of working servers, taking over:

load balancing of internal and geographically distant servers;

managing connections with multiple providers and choosing the most suitable connection;

analysis of packets at all levels of the OSI model, from 4th to 7th, and resisting any unauthorized access attempts;

user authentication and authorization;

caching web pages with all kinds of customization functions;

performing SSL encryption and decryption.

BIG-IP software modules run on a single TMOS (Traffic Management Operating System) platform, which ensures their maximum efficiency in collaboration and facilitates centralized management of the entire system.

F5 BIG-IP Virtual Edition is a virtual application delivery controller installed on all leading hypervisors (VMware vSphere, KVM and Community Xen, Citrix XenServer, Microsoft Hyper-V) and cloud services (Amazon AWS, Microsoft Azure, Google Cloud Platform) running on standard servers.

BIG-IP VE provides advanced application delivery services including advanced traffic control, acceleration, DNS, firewall and access control that run on dedicated hardware. VE software images are available for download and are easily ported between virtualized on-premises data centers, public and hybrid cloud environments.

VIPRION is a powerful hardware platform with the ability to increase or decrease its performance without any disruption to applications and services.

With BIG-IP solutions powered by the VIPRION platform, you can quickly deploy and scale your application delivery infrastructure to meet the changing requirements of your company. With VIPRION, there is no need to add new devices, you can simply increase the capacity of an existing platform!

With high bandwidth, connections and SSL efficiency, VIPRION can handle high workloads while maintaining high application availability and performance.

Responsibilities, tasks, skills of the system administrator (sysadmin)

Description and functions of the position of a system administrator

The profession “System Administrator” is the position of an IT specialist , whose duties include ensuring the smooth operation of computer equipment, local network and software (repair, regularly updating, setting up, etc.). And the demand for this specialty is constantly stable because no sphere of human activity can do without the use of computers linux administrator. 

Below, we present to you a list of responsibilities, skills and knowledge that are important to have in order to become a system administrator.

Is it easy to master the profession?

It is not easy to master the profession of a system administrator. mandatory requirements for a sysadmin are most often in-depth knowledge of the Windows family (for example, offices often use Active Directory to control the domain), free orientation in the hardware settings (wi-fi access points, routers, printers, etc.), the ability to organize / configure a computer local network (both physical and virtual) and so on. 

Sometimes companies hire young assistants for sysadmins (they are also called enikeys or specialists in everything), who are engaged in small tasks that often require not deep technical knowledge, but patience and free time (for example, install a program for accounting or reinstall Windows). In order to become an assistant to a system administrator, deep knowledge is not required (often people with burning eyes and a desire to learn and minimal technical skills are hired for it). With the proper approach, Enikeys gradually gain experience and in a year or two can become full-fledged administrators. 

Salary level

The salary level depends on the specialization (specializations can be, for example, a pure Windows admin, a Window / Linux admin, an admin for servicing virtualization systems such as VMware, universal specialists in all intra-office tasks), the depth of knowledge within the specialization, the size of the company and much more. Typically, the salary of a system administrator is higher than that of a technical support engineer or QA engineer (manual), but lower than that of DevOps or Developers.

Pros and cons of the profession of a system administrator

Pros:

good salary

a deep level of understanding of how modern IT works (since things that system administrators work with - from hardware to virtualization systems)

Minuses:

multitasking (many small tasks from a large number of employees)

often routine tasks (for example, reinstalling the system)