CST’s team of highly experienced design engineers can develop the complete process from the conceptual phase to the detail design through the most advanced and integrated computing tools such as Virtual Prototyping, Computational Fluid-Dynamics (CFD) and Multiphysics.
Virtual Prototyping is a software-based engineering discipline which involves modelling a system, simulating and visualizing its behavior in real-world operating conditions, and tuning its design through an iterative process. The process begins with creating 3D models, combining the geometries of parts and related assemblies with their load conditions. Models are defined by a commercial and a proprietary software for the simulation of kinematic and thermo-fluid dynamic behavior. It ends with a functional, structural and fatigue testing using linear and multiaxial nonlinear algorithms, depending on the specific part to be analyzed.
The ability to simulate multiple design interactions in a short amount of time results in a reduced prototyping cost. The time saved can be spent on other tasks related to product development like reliability, maintainability, and design for manufacturing, minimizing the time to market.
Virtual Prototyping involves:
- Computer-aided design (CAD)
- Computer-aided engineering (CAE)
- Performance Software CST “Reciperf”
- Finite Element Analysis (stress, temperature distribution, flow etc.)
- Linear or Multi-Axial Fatigue.
- Added modules that perform various other tasks, such as prototype manufacturing, product life cycle management, etc.
Virtual Prototyping allows to simulate complete machines and to apply loads as in a real physical object. Key design benefits:
- Multiple tests possibility during the development of the project, thus real optimization of the design
- Accurate evaluation of the contribution of various loads than what can be achieved on a real physical prototype
- "See" things that could not be seen on a real prototype (virtual prototype is a full body model “instrumented” at all points)
- Significant cost and time savings
- Avoid (or drastically reduce) the need for a physical prototype
Stress analysis is not sufficient in the design of reciprocating machines, such as compressors, pumps, and engines. In fact, the criticality of these machines comes mainly from the large fluctuation of the loads which makes them subject to fatigue. Therefore, it is mandatory to take care of the stress fluctuation induced by the load variation and determine the fatigue safety factor by means of the appropriate method. Depending on the type of load variation, material and elastic or elastic-plastic situation, CST utilizes many different fatigue criteria including:
- Von Mises
- Dang Van
- Brown Miller
Compressor Cylinder Fuid-Dynamic Analysis
For some compressor components, such as the cylinders, in addition to the mechanical/fatigue design is necessary also a fluid dynamics check to enable the best energy management. CST has developed a dedicated software for cylinder fluid-dynamic optimization (CylOpt) that helps to define the best shape of the gas passages before undergoing a 3D Computational Fluid Dynamics (CFD) analysis.
Thanks to all these professional design tools, CST has successfully developed the complete design of several new machines, from the conceptual phase to the manufacturing specifications.
Fluid Structure Interaction
In some special cases, when it is necessary to investigate at deep the interaction between a fluid and a mobile mechanical component or when in presence of a two-phase fluid, CST special Fluid Structure Interaction software faces the duty of making the investigation.
The video aside shows the FSI done by CST to study a special case of movement of the valve rings during the opening time.
Modernization & Upgrades
CST machine design know-how applies also for improvement of existing reciprocating compressors, by eliminating recurrent problems, helping users to increase the reliability of their plants, reducing operating costs.