Effect of carbon based nanoadditives on external gear pump performance

Abstract Effect of fine graphite flake, carbon nanotube, and carbon nanofiber additives on the efficiency of an external gear pump driving an ethanol-based closed hydraulic loop was investigated experimentally. A number of graphite, carbon nanotube (CNT) and carbon nanofiber (CNF) dispersions in ethanol were prepared with concentrations ranging from 194- 1500 ppm. The fluids were investigated in an external gear pump with a maximum operating pressure of 100 psi. Pump inlet pressure, volumetric flow rate, and electric power consumption data were recorded over a range of pump discharge pressures. The power consumed by the motor at a given differential pump pressure was found to remain approximately constant for all additive concentrations. It was found that increases in both volumetric flow rate and overall pump efficiency were observed when pure ethanol was replaced by the colloidal suspensions. This was attributed to a roller bearing effect caused by the alignment and self-lubrication of the colloidal additives when confined to micro-scale clearances between the gear surfaces. It was found that that pump performance was also a function on the CNT aspect ratio and could very from pump to pump, or even after a pump was disassembled and reassembled. This indicates that the clearance geometry between the gears and between the housing may play a critical role. To examine any potential structural changes in the additives, environmental scanning electron microscope (ESEM) images of the additives were obtained before and after extended run periods within the pump. The results indicate that graphite and CNTs retained significant resilience, i.e. no breakage and deformation was observed. However, the very long aspect ratio CNFs appear to have undergone some scission. To examine any issues with filterability, iii graphite and CNT suspensions were run through two filters of different size and composition and the filters where then qualitatively examined using ESEM images. The results indicate that a considerable amount of the additives were filtered from the suspension. This indicates that filterability is an issue that needs to be addressed if these suspensions were to be used in industrial applications.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Aerospace Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2012

Author dc:creator

• Martorana, Philip J.

Contributors dc:contributor

• Loth, Eric
• Bayer, Ilker

• External gear pump
• Nanoadditives
• Carbon Nanotube (CNT)
• Carbon Nanofibers (CNF)

Statement dc:rights

• Copyright 2011 Philip J. Martorana

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/29698

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/29698