Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
Scientific and Technical Aerospace Reports Volume 39 April 6, 2001
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egulations. The trends observed may eventually help explain effects of parameters such as injection pressure <strong>and</strong> orifice diameter<br />
on emissions.<br />
NTIS<br />
Combustion Chemistry; Injectors; Diesel Fuels; Diesel Engines; Sprayers; Launching; Fuel Sprays; Flames; Fuel Injection<br />
<strong>2001</strong>0026181 Oak Ridge National Lab., TN USA<br />
Aluminum R <strong>and</strong> D for Automotive uses <strong>and</strong> the Department of Energy’s Role<br />
Hadley, S. W.; Das, S.; Miller, J. W.; Mar. 01, 2000; 32p; In English<br />
Report No.(s): DE00-763142; ORNL/TM-1999/157; No Copyright; Avail: Department of Energy Information Bridge<br />
Although aluminum has achieved tremendous growth in the automotive market over the past decade, it has largely been in<br />
the specific areas of engine components, transmissions, wheels, <strong>and</strong> heat exchangers. Further growth is dependent on an increasing<br />
penetration into the engine block market <strong>and</strong> new structural components such as the BIW <strong>and</strong> closure panels. The cost of engine<br />
blocks is hampered by the need for <strong>and</strong> cost of cylinder liners. The cost of aluminum auto body sheet is still in the $1.30 range<br />
or higher, 30% above the $1/lb that is regarded as the price for aluminum to be widely used. This is also higher than the $1.10<br />
to $1.20 that new tailor welded blanking technologies may be economic. Forming <strong>and</strong> joining technologies are needed for aluminum<br />
to be more widely used in the BIW structure, <strong>and</strong> high-volume designs that utilize aluminum’s strengths would improve penetration.<br />
Research involving lower-cost processes or alloys must continue before aluminum can further penetrate these markets.<br />
DOE-funded research is important to these areas, <strong>and</strong> it satisfies the needs of the industry. The currently funded DOE research<br />
seems to have the right mix of cast <strong>and</strong> wrought aluminum projects. Several projects concentrate on the development of databases<br />
<strong>and</strong> predictive models to enhance the application of aluminum in automotive applications. Significant advances have been made<br />
in the rapid prototyping of cast aluminum parts <strong>and</strong> forming of wrought aluminum parts. Further work is needed in the validation<br />
of tools developed by means of demonstration in actual automotive parts.<br />
NTIS<br />
Aluminum; Research <strong>and</strong> Development; Automobiles; Structural Design; Market Research<br />
<strong>2001</strong>0026202 S<strong>and</strong>ia National Labs., Albuquerque, NM USA<br />
Disturbance Rejection Control of an Electromagnetic Bearing Spindle<br />
Petteys, R.; Parker, G.; Aug. 31, 2000; 8p; In English<br />
Report No.(s): DE00-761889; SAND2000-2183C; No Copyright; Avail: Department of Energy Information Bridge, Microfiche<br />
The force exerted on the rotor by an active magnetic bearing (AMB) is determined by the current flow in the magnet coils.<br />
This force can be controlled very precisely, making magnetic bearings a potential benefit for grinding, where cutting forces act<br />
as external disturbances on the shaft, resulting in degraded part finish. It is possible to achieve precise shaft positioning, reduce<br />
vibration of the shaft caused by external disturbances, <strong>and</strong> even damp out resonant modes. Adaptive control is an appealing<br />
approach for these systems because the controller can tune itself to account for an unknown periodic disturbance, such as cutting<br />
or grinding forces, injected into the system. In this paper the authors show how one adaptive control algorithm can be applied to<br />
an AMB system with a periodic disturbance applied to the rotor. An adaptive algorithm was developed <strong>and</strong> implemented in both<br />
simulation <strong>and</strong> hardware, yielding significant reductions in rotor displacement in the presence of an external excitation. Ultimately,<br />
this type of algorithm could be applied to a magnetic bearing grinder to reduce unwanted motion of the spindle which leads<br />
to poor part finish <strong>and</strong> chatter.<br />
NTIS<br />
Electromagnetic Fields; Magnetic Bearings<br />
152<br />
<strong>39</strong><br />
STRUCTURAL MECHANICS<br />
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<strong>2001</strong>0022809 Massachusetts Inst. of Tech., Lincoln Lab., Lexington, MA USA<br />
Gaussian Patterned Contacts for Improved Beam Stability of 1.55 Micrometer Untapered Lasers<br />
Walpole, James N., Massachusetts Inst. of Tech., USA; Donnelly, J. P., Massachusetts Inst. of Tech., USA; Missaggia, L. J., Massachusetts<br />
Inst. of Tech., USA; Liau, Z. L., Massachusetts Inst. of Tech., USA; Chinn, S. R., Massachusetts Inst. of Tech., USA; Groves, S. H., Massachusetts<br />
Inst. of Tech., USA; Taylor, P. J., Massachusetts Inst. of Tech., USA; Wright, M. W., Air Force Research Lab., USA; IEEE Photon-
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