ARKS TE - simulating Thermal Explosion in solids

Purpose of the program

ARKS TE software package (the heir of ThermEx) is the analog-free powerful tool for simulation of thermal explosion in solids and highly viscous liquids when thermal conductivity governs internal heat transfer whereas convection and diffusion can be ignored. It is one of the key components of the TSS-ARKS software. ARKS TE works with formal kinetic models of chemical reactions. To avoid possible confusion note that the term "thermal explosion" here means the same physical event that is often referred to as "slow cook-off". It doesn't have anything in common with detonation.. 

The project-oriented User's interface visualizes structure of the project to be simulated, provides easy access to every project's component. It such a manner the interface guides you along all the steps of the problem solution.

ARKS TE inherits the best features of its predecessor ThermEx Standard and has many new qualities, including enhanced set of the objects that can be simulated, new interface, essentially reworked solvers based on improved algorithms, videotutorials to help in mastering software: 

TE Tutorial 1 Properties DB
TE Tutorial 2 Runaway simulation
TE Tutorial 3 SADT determination

TE Tutorial 4 Critical conditions

From physical and mathematical point of view simulation of thermal mode of a solid object (and its special case - thermal explosion) comes to numerical integration of partial differential equation of thermal conductivity with exothermic reaction as the internal source of energy. Existence of critical conditions that separate explosive and non-explosive domains, possible sharp gradients of temperature and conversions that may appear, and some other factors complicate calculations; therefore, special attention has been paid to careful selection and adjustment of the mathematical methods.

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Handling data

ARKS TE is based on the project concept. A project unites all the components necessary for simulation – kinetic model, object description (geometry, size, boundary conditions), physical properties of a reacting substance and construction materials, type of simulation, parameters of numerical method.

Projects are stored in the internal database. Database consists of data volumes. Every data volume includes number of projects.

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Kinetics

ARKS TE uses the formal kinetic models. They can be created in ARKS FK and imported into a project. For this purpose ARKS TE provides direct access to the ARKS FK data base which allows easy import of kinetic models; kinetics can also be defined manually by the User.

Formal model based on conversion degree as state variable can represent a complex multi stage reaction including reversible reactions, pressure-dependent reactions, reactions having branched pathways.

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Physical properties

ARKS TE provides simulations taking into account demperature-dependent physical properties of a substance and material of a container. All the properties necessary for simulation: heat capacity, thermal conductivity, density, vapor pressure (if a substance contains some volatile components) are accumulated in the internal properties data base which can be replenished by the user. This database is similar to the properties databases used in ARKS FK,  ARKS CK, ARKS HA and ConvEx FK/DK.

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Boundary conditions

TE-Standard allows simulation of an object under boundary conditions (BC) of the following types:

• BC of the first kind - temperature on the outer surface is defined;
• BC of the second kind - heat flux on the outer surface is defined;
• BC of the third kind - convective heat exchange in accordance with Newtonian low.

Parameters of BC can be either constant of defined as tabular functions of time. Furthermore, individual BC can be defined on every surface of the two- or three-dimensional object.

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Geometries supported by TE-Standard

The module supports set of objects of predefined geometry. Three classes of problems can be simulated:

• One-dimensional problem: infinite cylinder, infinite slab, sphere; inert partitions and inert shell are available.

• Two-dimensional problem: partly or fully filled cylindrical barrel; inert shell and coaxial partitions are available. Simulation of reaction and estimate of pressure rise due to appearance of gaseous products and vapors in the viod volume of a barrel. The possibility is foreseen to simulate partly filled shelled barrels with spherical, elliptical or conical lids.

• Three-dimensional problem: partly filled shelled rectangular box or bin (box with prismatic lower section). Simulation of reaction and estimate of pressure rise due to appearance of gaseous products and vapors in the box/bin void volume.

     

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Simulation modes

To make use of ARKS TE easier three specialized simulation modes are offered:

• Runaway – simulation of thermal explosion development, estimate of induction period of an explosion;​
• Critical search - automated determination of critical temperature and induction period for the object of the defined geometry and size; ​
• SADT/SAPT - automated determination of the Self Accelerating Decomposition Temperature (SADT) in accordance with the United Nations Recommendations on Transport of Dangerous Goods

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Convenient way of results presentation

Results of simulation are presented in graphical form as evolutional curves (temperatures, pressure, conversions), in form of the Color Gradient view of temperature distribution during the simulation, in the 3-D plot for 2- and 3-dimensional objects, and as isolines for temperature and concentrations. 

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Animator

When running simulation a User can request for recording current results and, in this way, creating a movie for detailed analysis of the results after simulation is completed. Then a movie can be played by the Animator - the auxiliary module which can be run either from under ARKS TE or separately in autonomous mode.

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ARKS TE-Pro (coming soon)

This unique module is designed for simulation of user-created objects of complex geometry. Two classes of objects can be created:

• User-defined set of infinite rods (rectangular, triangular,  round or elliptical); overlapping and mutual penetration are allowed; every rod may have its own unique properties including kinetics
• User-defined set of axially symmetric solid objects obtained by the rotation around the vertical axis; overlapping and mutual penetration are allowed; every part may have its own unique properties including kinetics.

TE-Pro utilizes original method of generating irregular spatial grid based on triangles or Voronoy cells. Numerical simulation is implemented by applying the method based on the concept of control volumes.

Results of simulation are presented in graphical form as evolutional curves (temperatures, conversions), and on the 3-D plot.

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Installation

ARKS TE is compatible with Windows  7, 8, 10, 11

ATTENTION!

1.  When installing the program under Windows 7 and higher we strongly recommend to use the default path  C:\Users\[username]\CISP\[program]
2. When installing new versions of TSS-ARKS applications one can meet the problem with Anti-virus tools you use.  Some of them may suspect that TSS-ARKS programs are hazardous ones. Please don't worry. This may happen  due to new  powerful protection system (provided by  the Enigma Protector - one  of the world  leaders in this  area) which  sometimes causes alarm because anty-virus tools cannot look  inside the protected code. As a result the approcation will be blocked. To avoid such problem ask your IT service to exclude .Users\[username]\CISP  folder from virus  check  ​
   CISP guarantees that TSS -ARKS is 100% clean, which means its applications do not contain any form of malware, including but not limited to: spyware, viruses, trojans and backdoor.
3. Be aware - even if you are the licensed user of this program you will have to get new registration key. Please email us the request and don't forget to indicate your company and your name
4. IMPORTANT! ARKS TE.exe should be run with the Administrator rigghts; therefore  assign this right as follows:  find the ARKS TE.exe in the Thermal safety group of the Start Menu, right click and select 'Run as administrator'.

Requirements:

CPU: Multi-core Intel or AMD 1200 MHz and faster recommended
Memory: 1024 MB and more
isk space: 500 MB
CD-ROM: present
OS: MS Windows  7, 8, 10, 11

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Be aware - even if you are the licensed user of TSS or TSS-ARKS software with valid guarantee or maintenance, when you upgrade ThermEx to ARKS TE  you will have to get new registration key. Please email us the request and don't forget to indicate your company and your name  

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IMPORTANT! Be aware that on the expiration of the Warranty/maintenance Period the License on any TSS or TSS-ARKS application remains valid for the version last updated during maintenance Period. Therefore, if your maintenance has expired you wouldn't be able to use new updates. If you nevertheless download the setup of new version and replace your working version with new one it won't work and you will lose working program! To avoid such situation check please whether you have valid maintenance before downloading any TSS-ARKS program.