Analysis of Interfacial Processes on Non-Wetting Surfaces

Non-wetting surfaces mainly categorized into superhydrophobic (SHS), lubricant-infused (LIS) and solid-infused surfaces (SIS), by virtue of their superior water repellant properties have wide applications in several energy and environmental systems. In this dissertation, the role of non-wetting surfaces toward the enhancement of condensation effectiveness is analyzed by taking into consideration the tube side and shell side individual interfacial energy transport processes namely, drag reduction, convection heat transfer enhancement, fouling mitigation and dropwise condensation heat transfer. First, an analytical solution is developed for effective slip length and, in turn, drag reduction and friction factor on structured non-wetting surfaces. Secondly, by combining the solution for effective slip length on structured non-wetting surfaces and the fractal characterization of generic multiscale rough surfaces, a theoretical analysis of drag reduction, friction factor, and convection heat transfer enhancement is conducted for scalable non-wetting surfaces. Next, fractal representation of rough surfaces is used to theoretical derive the dropwise condensation heat transfer performance on SHS and novel SIS surfaces. The aspect of dynamic fouling mitigation properties of non-wetting surfaces is explored by conducting systematic experiments. Using Taguchi design of experiments, this work for the first time presents a closed formed relationship of fouling mitigation quantified in terms of asymptotic fouling resistance with Reynolds number, foulant concentration and viscosity of the infusion material that represents the different surface types in a unified manner. Furthermore, it was observed that LIS and SIS offer excellent fouling mitigation compared to SHS and conventional smooth surfaces, however only SIS owing to the presence of solid-like infusion materials is observed to be robust for practical applications.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2022

Author dc:creator

• Hatte, Sandeep Shankarrao

Chair dc:contributor.committeechair

• Pitchumani, Ranga

Committee members dc:contributor.committeemember

• Davalos, Rafael V.
• Cheng, Jiangtao
• Mahajan, Roop L.

• Non-wetting surfaces
• superhydrophobic surfaces
• lubricant-infused surfaces
• solid-infused surfaces
• drag reduction
• convection
• condensation
• fouling

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:35457

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/112074