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Mechanical Engineering. 2012;134(12):28-32. doi:10.1115/1.2012-DEC-1.
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This article presents an overview of the emerging field of biomimetics. Biomimetics is highly interdisciplinary and is gaining a foothold in the scientific and technical arena. Biomimetics involves the understanding of biological functions, structures, and principles of various objects found in nature by biologists, physicists, chemists, and material scientists, and the design and fabrication of various materials and devices of commercial interest from bioinspiration. Today, biomimetic materials are moving out of the laboratory and into industrial applications. Significant advancements in nanofabrication allow engineers to replicate structures of interest in biomimetics using smart materials. The commercial applications include nanomaterials, nanodevices, and processes that may enable self-cleaning surfaces or pads that hang pictures without hooks or wires. Some of these applications may at first seem magical, but they simply are the result of applying science and engineering to uncovering the secrets of nature.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):34-37. doi:10.1115/1.2012-DEC-2.
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This article reviews the computational technology being developed by the Team for Advanced Flow Simulation and Modeling (T*AFSM) at Rice University in Houston and Waseda University in Tokyo that can reliably predict the performance of various NASA parachute designs. The data from these simulations permit NASA to focus on a few of the most promising designs for testing, and also lets designers explore a greater number of alternative designs. The T*AFSM modeled a base design that NASA put through a drop test over the desert, and the team was very pleased to see that the predictions of its model held up well against data from that NASA test. For instance, the computer model predicted a descent speed of 21.4 feet per second, which was within 10% of the average speed observed in the test. Other predictions—such as the rate of swinging and breathing periods—were well within 10% of the observed behavior of parachutes in the physical test.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):38-41. doi:10.1115/1.2012-DEC-3.
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This article discusses the advantage of compressed air energy storage (CAES) system. CAES has been proposed as an alternative to pumped hydro storage for large-scale, bulk energy management. CAES systems typically rely on electrically driven air compressors that pump pressurized air into large underground geological formations such as aquifers and caverns for storage. When the power is needed, turboexpanders connected to generators convert the compressed air back into electrical energy. Like pumped hydro, CAES can be scaled to sizes compatible for supplementing large renewable energy facilities. The lifetime costs for a CAES system can make it work as a means for storing cheap off peak electricity and selling it during peak hours, but capital costs and difficulties finding suitable geological structures have limited the technology’s applications. To make CAES more useful for storing wind-powered electricity, the systems have to become less expensive and have greater flexibility in sitting.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):42-45. doi:10.1115/1.2012-DEC-4.
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In this article, Samuel C. Florman, the chairman of Kreisler Borg Florman General Construction Co. recalls how a sequence of events in 1963 led his young construction firm to $2 million in billings at the World’s Fair. During the summer of 1962, Norman Winston was appointed as the United States Commissioner to the World Fair. He was specifically charged with supervising development and construction of an American pavilion. The construction contract for the pavilion had gone to famous developer Del Webb. However, in late 1963, due to some issues, Del Webb walked out of the project. The job of finishing the federal pavilion was then offered to Florman’s firm. Florman’s firm was to perform miscellaneous finishing items and provide “general oversight.” While the original fee of the firm was a measly $45,000, the amount grew rapidly as the scope of the activities increased. By the time the Fair closed in 1965, Florman’s firm had billed some $2 million on which it earned approximately 20% in gross profit.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):50-54. doi:10.1115/1.2012-DEC-5.
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This article investigates the influence of GT Model and Spool Arrangement on solar hybrid combined cycle (CC) performance. To investigate the way the GT interacts with the solar system, two commercial codes were used. A “user-defined” GT model was first developed on the basis of design conditions performance, then carefully calibrated against manufacturer data to accurately predict its off-design behavior depending on load and ambient temperature conditions. To assess the influence of GT model and spool arrangement on the solarized CC performance, the following GTs were selected: the single-shaft Siemens SGT800 and two two-shaft engines: the heavy-duty GT Siemens SGT750 and the aeroderivative GE LM6000. It was observed that the single-spool SGT-800 assures the lowest power penalty. The SGT-750 appeared to provide the highest fuel saving in the middle of the day, both in winter and summer, and the highest solar fraction as well.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):51. doi:10.1115/1.2012-DEC-6.
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This article discusses how incidents of bird strikes with jet engines can be avoided. According to a US Department of Transportation report, bird strikes have steadily and dramatically increased from 1770 reported in 1990 to 9840 in 2011, representing a fivefold increase in 20 years. The rise in strikes, as in other parts of the world, is due in part to sizable increases in large bird populations. According to the DOT report, since 1988, bird strikes have resulted in 229 deaths worldwide. Annually, these incidents have caused nearly 600,000 hours of aircraft downtime, and $625M in damages. All commercial jet engines must comply with bird ingestion regulations established by worldwide regulatory authorities. These regulations are all similar and call for demonstrations of an engine’s ability to ingest birds in small, medium, and large categories. Not being able to meet these regulations can have serious consequences for an engine company.

Commentary by Dr. Valentin Fuster
Mechanical Engineering. 2012;134(12):52-53. doi:10.1115/1.2012-DEC-7.
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This article discusses the results of experimental investigation of turbulent boundary layer flashback limits for premixed hydrogen-air flames confined in ducts. A tube burner experiment was set-up to double-check the findings of the channel rig. Unconfined flashback experiments were carried out by stabilizing the flame on top of the pilot burner in free atmosphere. A confined flame configuration was achieved by simply fixing a ceramic ring with a diameter higher by 4 mm on top of the pilot burner. Flashback measurements with unconfined flame holding neatly reproduced literature values for fully premixed, atmospheric H2–air mixtures and turbulent flow. The results of unconfined and confined tube burner experiments were plotted. The results showed that the drastic decrease of wall flashback stability for confined flames was the very same for both, tube and channel.

Commentary by Dr. Valentin Fuster

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