Scalable and Resilient Etched Metallic Micro- and Nanostructured Surfaces for Enhanced Flow Boiling

2021 ◽  
Author(s):  
Nithin Vinod Upot ◽  
Allison Mahvi ◽  
Kazi Fazle Rabbi ◽  
Jiaqi Li ◽  
Anthony M. Jacobi ◽  
...  
Keyword(s):  
Flow Boiling ◽  
Nanostructured Surfaces

Biotemplated Nanostructured Surfaces for Enhanced Phase Change Heat Transfer

2012 ◽  
Author(s):  
S. M. King ◽  
Md. M. Rahman ◽  
A. K. Krick ◽  
L. D. Branco ◽  
E. Olceroglu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Tobacco Mosaic Virus ◽  
Phase Change ◽  
Mosaic Virus ◽  
Self Assembly ◽  
High Speed ◽  
Flow Boiling ◽  
Structured Surfaces ◽  
Nanostructured Surfaces ◽  
Phase Change Heat Transfer

The fabrication and characterization of biotemplated nanostructured coatings based on the Tobacco mosaic virus for enhanced phase-change heat transfer is reported. A simple room temperature nanofabrication process, using the self-assembly and mineralization of the Tobacco mosaic virus (TMV), has been implemented to create superhydrophilic surfaces. Using this technique, a variety of structured surfaces have been fabricated and characterized showing enhanced surface wettability and heat transfer characteristics. High-speed images of droplet impact evaporation on flat and hierarchical samples have been recorded, showing increased wetting and evaporation for the nanostructured surfaces. The addition of nanostructures increases the heat transfer rate by more than a factor of three as compared to the flat surfaces, and hierarchical surfaces exhibit heat transfer rates more than an order of magnitude larger than flat non-structured surfaces. Additionally, an increase in Leidenfrost temperature of 100°C as compared to flat samples has been recorded. TMV nanostructures were also assembled onto the walls of heated minichannels, promoting continuous bubble detachment as well as reduced slug formation and instabilities during flow boiling. While bare minichannel exhibits nearly complete dry-out, the nanostructured channels maintain annular flow at similar loadings. This work demonstrates the feasibility of enhancing phase-change heat transfer using TMV structured coatings.

Investigation of Flow Boiling on Nanostructured Surfaces

2010 ◽  
Author(s):  
Saeil Jeon ◽  
Pratanu Roy ◽  
N. K. Anand ◽  
Debjyoti Banerjee
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Silicon Surface ◽  
High Speed ◽  
Flow Boiling ◽  
Copper Surface ◽  
Heat Fluxes ◽  
Test Fluid ◽  
Nanostructured Surfaces ◽  
Layer Effect

Flow boiling experiments were performed on copper, bare silicon and carbon nanotube (CNT) coated silicon wafer using water as the test fluid. Wall heat flux was measured by varying the wall superheat. The experiments were performed under pool boiling conditions (zero flow rate) as well as by varying the flow rates of water. The liquid sub-cooling was varied between 40 ∼ 60 °C. An infra–red camera was used to calibrate the surface temperature of the silicon wafers and the copper surface. Heat flux measurements were performed by using a calorimeter apparatus. High speed visualization experiments were performed to measure the bubble departure diameter, bubble departure frequency and bubble growth rate as a function of time. Heat flux values for all three surfaces were calculated from the temperature differences obtained by sheathed thermocouples inside the copper block in the calorimeter apparatus. Flow boiling curves were plotted to enumerate the enhancements in heat transfer. It was observed that MWCNT coated silicon surface enables higher heat fluxes compared to bare silicon surface. This enhancement can be ascribed to be due to the high thermal conductivity of the carbon nanotubes, micro-layer effect, enhancement of transient heat transfer due to periodic solid-liquid contact and increase in active nucleation sites on nanostructured surfaces.

Sign in / Sign up

Export Citation Format

Share Document