Heat Engine Driven by Shape Memory Alloys: Prototyping and Design

Schiller, Ean H.

Heat Engine Driven by Shape Memory Alloys: Prototyping and Design

dc.contributor.author	Schiller, Ean H.	en
dc.contributor.committeechair	Reinholtz, Charles F.	en
dc.contributor.committeemember	Leo, Donald J.	en
dc.contributor.committeemember	Robertshaw, Harry H.	en
dc.contributor.department	Mechanical Engineering	en
dc.date.accessioned	2014-03-14T20:45:57Z	en
dc.date.adate	2002-10-01	en
dc.date.available	2014-03-14T20:45:57Z	en
dc.date.issued	2002-09-19	en
dc.date.rdate	2003-10-01	en
dc.date.sdate	2002-09-25	en
dc.description.abstract	This work presents a novel approach to arranging shape memory alloy (SMA) wires into a functional heat engine. Significant contributions include the design itself, a preliminary analytical model and the realization of a research prototype; thereby, laying a foundation from which to base refinements and seek practical applications. Shape memory alloys are metallic materials that, if deformed when cold, can forcefully recover their original, "memorized" shapes, when heated. The proposed engine consists of a set of SMA wires stretched between two crankshafts, synchronized to rotate in the same direction. Cranks on the first crankshaft are slightly longer than cranks on the second. During operation, the engine is positioned between two distinct thermal reservoirs such that half of its wires are heated while the other half are cooled. Wires on the hot side attempt to contract, driving the engine in the direction that relieves the heat-induced stress. Wires on the cold side soften and stretch as the engine rotates. Because the force generated during heated recovery exceeds that required for cooled deformation, the engine is capable of generating shaft power. Limited experimental measurements of shaft speed were performed. An analytical model of the engine predicts that the maximum output power for the prototype, under test conditions, should be 0.75 W. Thermal efficiency, though not measured or calculated in this work, is expected to be low. Potential applications may include the conversion of waste heat into shaft power.	en
dc.description.degree	Master of Science	en
dc.identifier.other	etd-09252002-170731	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-09252002-170731/	en
dc.identifier.uri	http://hdl.handle.net/10919/35185	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	hg1.mpg	en
dc.relation.haspart	wbnf1.mpg	en
dc.relation.haspart	ETD.pdf	en
dc.relation.haspart	wbwf2.mpg	en
dc.relation.haspart	wbnf2.mpg	en
dc.relation.haspart	hg2.mpg	en
dc.relation.haspart	wbwf1.mpg	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	SMA	en
dc.subject	heat engine	en
dc.subject	shape memory alloys	en
dc.subject	Nitinol	en
dc.title	Heat Engine Driven by Shape Memory Alloys: Prototyping and Design	en
dc.type	Thesis	en
thesis.degree.discipline	Mechanical Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	masters	en
thesis.degree.name	Master of Science	en