Acoustic impedance is difficult to grasp intuitively since it is dependent on both material and geometry and is complicated by the fact that the velocity and pressure are not necessarily in phase. Yet it is critical that engineers get it right because it dictates efficient transfer of sound energy from point to point.
For many years, ANSYS has had 2D and 3D acoustic elements, including those used to model an "infinite" boundary. These elements can be used in modal, harmonic, and transient analyses, and fluid-structural interaction can also be accounted for in these simulations. The application of complex impedance on a boundary can be performed in ANSYS with the use of SURF153/154 elements.
The use of SURF153/154 allows users to model complex specific acoustic impedance at any boundary. The user, however, should run smaller models with known solutions first to become acquainted with this slightly unconventional modeling approach. The unique feature of these elements is that terms to the mass [M], damping [C], or stiffness [K] matrices can be added directly.
Advertised as the "Most Powerful Tablet Under $100," the Kindle Fire HD 6 was too tempting for the team at iFixit to pass up. Join us to find out if inexpensive means cheap, irreparable, or just down right economical. It's teardown time!
The increased adoption of wireless technology for mission-critical applications has revved up the global market for dynamic electronic general purpose (GP) test equipment. As the link between cloud networks and devices -- smartphones, tablets, and notebooks -- results in more complex devices under test, the demand for radio frequency test equipment is starting to intensify.
Much of the research on lithium-ion batteries is focused on how to make the batteries charge more quickly and last longer than they currently do, work that would significantly improve the experience of mobile device users, as well EV and hybrid car drivers. Researchers in Singapore have come up with what seems like the best solution so far -- a battery that can recharge itself in mere minutes and has a potential lifespan of 20 years.
Some humanoid walking robots are also good at running, balancing, and coordinated movements in group settings. Several of our sports robots have won regional or worldwide acclaim in the RoboCup soccer World Cup, or FIRST Robotics competitions. Others include the world's first hockey-playing robot and a trash-talking Scrabble player.
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