6926475942

Impulsiva low-frequertcy noise from wind turbinę* cen causa • nnoyence perticularly when a residential structura is in-volved. Such noise is typically genarated in some spatiałly restrictad region of a turbin* rotor swept araa. Low-frequen-cy impulsiy* noisa of tha MOD-1 turbina ganaratad wwhan tha rotor blada* patsed downwind of tha towar lag* •ncountaring tha complex unstaady flows ther*. Anacoustic ranging tachniqua that aid* assassmant of tha dagrae of concantrat ion of acoustic ganaration within tha turbina •wapt araa and which dat ar min es tha time«verage spatial •ourca region of auch concantration i* described. Practical application* and (imitations of tha proces* ara discutsed.

Conversion Engrg. Conf., Orlando, FL. Aug 21,1983) DE83017283

Kay Word*: Internat combustion anginę*

The dynamie behavior of the liquid-pi*ton Stirling engine i* analyzed using the vector or phaaor method of representing the motion*of coupled system*. The re*ult, for the first time, i* a simple physical explanetion of the feedback machaniem most frequently employed in th**e machina*. In addition, the method leeds to an aasy denvat>on of certain results already known from experiment or from morę complex analysas.

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RECIPROCATING MACHINES

(Also see No*. 1570)

84-1573

Buic Research on Yibration and Noiae of Intemal Combustion Engine (lal Report, Yibration Anałyas of the Puton-Crank System I)

M. Nagaikeand A. Nagamatsu Tokyo Inst. of Tech., 12-1, Ohokayama 2-chome. Meguro-ku. Tokyo, 152, Japan, Buli. JSME. 27 (224), pp 289-294 (Feb 1984) 15 figs, 1 table. 4 refs

Kay Word*: Intarnal combustion angin**, Substructuring mathods, Building błock approach. NaturaI frequancies. Moda shapas. Transfer function*

A vft>ration analysis of tha piston-crank system of an intarnal combustion angina « mada. Tha system is composed of thraa sub*tructur*»: a piston, a connecting rod, and a com-bined system of a crankshaft and a flywhaat. Tha transfer function* of aach substructura ara obtained by the raducad impadanca method. Tha transfer function* of a baaring ara obtainad axparimantally by tha harmonie exciting test. Netural fraquancie*, natura! moda* and transfer function* of tha whole body ara dttarminad with tha transfer func* ttons of aach substructura and baaring part* by tha building błock approach.

84-1575

Forced Oscillation Expenments in Supercritical Diffuser Flows

M. Sajben, T.J. Bogar, and J.C. Kroutil McDonnell Douglas Corp., St. Louis. MO, AIAA J., 22 (4). pp 465-474 (Apr 1984) 16 figs. 1 table. 17 refs

Kay Word*: Jet angina*. Combustion excitation, Vibratk>n response

Low4raquancv oaciltotiont inducad In ramjat inlet* by combustion instabilities wara simulated by machanically modułating the exit araa of a two-dlmension*!, supercritical diffuser at frequencies up to 330 Hx. Boundary layars wara attachad below a terminal shock Mach number of 1.27, and shock-induced separation occurred above this value up to the experimental limit of 1.35. Shock position historie* were obtained and streamwise distributioni of static/total dynamie pressures were determlned both on the wali and wKhin tha flow for various shock strengths and fraquencies. Excitation •t tha natural fraquencias of tha shock motlon producad no obvk>us resonance effaets.

METAL WORKING AND FORMING

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84-1574

Dynamie Anałyna of the Fluidyne

C.D. West

Oak Ridge National Lab., TN, Rept. No. CONF-830012-49, 27 pp (1983) (18th Intersociety Energy

84-1576

Devełopment and Application of Multipłe Input Modela for Structural Noiae Source Identification of Forge Hammera. Part I: Deyelopment

M.W. Trethewey and H.A. Evensen Pennsylvania State Univ., University Park, PA 16802. J. Acoust. Soc. Amer., 75 (4), pp 1092-1098 (Apr 1984) 10 f igs, 32 refs

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