Rotating machinery (or turbomachinery) is an application area that spans many industry segments. Each of these significantly influences the performance and efficiency of the entire system. Rotating machinery also covers a range of different scales from very large hydraulic turbines (10m diameter runner), steam and gas turbines to small automotive turbochargers that can fit roughly in the palm of our hand. Improving the performance of rotating machinery has long been realized as a crucial factor in the success of the system as a whole. Continue reading
Industry consolidation was one topic of discussion as my colleague-in-turbomachinery Bill Holmes and I and recently returned from the Turbomachinery & Pump Symposia. The event is organized by the Texas A&M University Turbomachinery Laboratory and held at the George R. Brown Convention Center in Houston Texas. Only a few years back the pump and turbomachinery shows were separate. With the amalgamation one is now able to view a large array of impressive hardware and attend informative technical sessions applicable to the full range of equipment: pumps, compressors, turbines, fan, blowers and all related components and services. The emphasis is on Oil & Gas machinery, although not exclusively as there are synergies with power generation, chemical process, air separation etc. Continue reading
Many structural engineers face the challenge of mapping (interpolating) data — such as pressures, thicknesses or temperatures — on a finite element mesh (also known as point cloud data mapping). This often happens within companies where the analysts performing CFD or thermal analyses are not the ones performing the structural analyses. This also happens when the company is using tools from different providers.
Common data that analysts need to import as boundary conditions are pressures and temperatures. For example, think of a gas turbine where pressure and temperature results from the CFD computations need to be used for the structural analysis.
Are you dealing with assemblies? Then you need some sort of contact modeling. Are you designing products with plastic or rubber parts? You need an appropriate nonlinear material model. Are you dealing with large deformations? You need to include the effects of geometric nonlinearities.
If you do technical support long enough you will discover there are only ten questions. Of course there are a myriad of small difficulties, irritations, limitations and complaints that customers call in about, but I’m not talking about those. I’m referring to questions which are almost philosophical in nature. In my area of linear dynamics, one of the ten is, “Should I do a response spectrum analysis?”
What job could be more fun than supporting a general purpose program like ANSYS Mechanical? You get to use ANSYS multiphysics technology and your engineering knowledge to solve many small mysteries, such as: Why doesn’t my model satisfy equilibrium? My solution doesn’t match my hand calculations. You also get to be a coach: How do I model a permanent magnet? One day you’re a stress analyst, the next an amateur scientist. I have to admit I sometimes feel more like Dr. Frankenstein’s assistant than a scientist.
Ratchetting refers to the progressive increase in plastic strain in a structure under nonsymmetric cyclic loading. The accumulated plastic strain increases without bound as the cyclic loading continues. Shakedown is similar to ratchetting except that the plastic strain progressively stabilizes under nonsymmetric cyclic loading. As the cyclic loading continues, the accumulation of plastic strain eventually stops.
Both ratchetting and shakedown can be simulated using ANSYS Mechanical software.
After performing a conjugate heat transfer (CHT) simulation in ANSYS Fluent or ANSYS CFX software, you may be interested in the thermal stresses generated in your model. ANSYS Workbench 13.0 makes it easy to perform this type of analysis by transferring the volumetric temperature field from your CFD solution and applying it as a body temperature load in a static structural system. Continue reading
Product development organizations know that simulation has become a natural part of the design process. But how efficient is your simulation process? Do you really get the most out of your simulations?
Many common processes such as those in manufacturing and transportation produce random vibration loading. To ensure the structural integrity of components subjected to these processes, the fatigue damage caused by vibration loading must be assessed. ANSYS Mechanical and ANSYS nCode DesignLife software can be used to estimate the fatigue life of components subjected to random vibration loading.