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Aditya Narayan

M.S., Advanced Materials and Technologies Laboratory, 2017
Aditya Narayan


Aditya Narayan received a Master of Science degree from the Advanced Materials and Technologies Laboratory at Virginia Tech. He received his Bachelor’s degree in Mechanical Engineering from the Manipal Institute of Technology, Manipal, prior to joining the Laboratory in Spring 2016. His primary research interests are in fluid/thermal Science, membrane distillation and solar concentrators. 

Research Projects

Air-cooled Air Gap Membrane Distillation

An air-cooled design for an air gap membrane distillation (AGMD) process offers potential for significantly lowering energy requirements and reducing cost for desalination by eliminating or reducing the balance of plant components associated with the coolant flow system. Experiments were conducted on an air-cooled AGMD module to study the effects of air gap, support mesh conductivity and hydrophobicity, and the condensing surface hydrophobicity. A novel modular design was developed in which modules could be arranged in a series configuration to increase the distillate flux. The output from the series configuration was found to yield about three times the distillate water compared to a single pass water-cooled system with the same temperature difference. The results also indicate that the mesh conductivity has a favorable effect on the flux value whereas the hydrophobicity of the mesh has no significant effect. The hydrophobicity of the condensing surface is favorable on two accounts: first, it increases the distillate flux at temperatures below 60 degrees C and secondly, the temperature difference of the saline feed when it enters and leaves the module is lower, which can lead to energy savings and higher yield when used in a series configuration.  

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Our AGMD design provides excellent purity.
Our AGMD design provides excellent purity.

Novel Radial Waveguide Concentrator for Concentrated Solar Thermal Applications

Non-imaging concentrators based on optical waveguides have the potential to provide a low cost solar collection for concentrated solar thermal applications through the elimination of moving parts and tracking structures. The primary working principle involves collection and transport of light through total internal reflection within an optical waveguide onto thermal receivers. This study explores the optical and thermal transport characteristics of radial waveguides integrated to a linear receiver. An analytical closed-form solution for the coupled optical and thermal transport of solar irradiation through a radial planar waveguide concentrator integrated with a linear receiver is developed. The effects of various design and operating parameters on the system performance, which is quantified in terms of net thermal power delivered, aperture area required and collection efficiency are discussed. Design constraints due to thermal stress, maximum continuous operation temperature and structural loading were considered to identify feasible waveguide configurations. A cost analysis is conducted to determine the preferred design configurations that minimize the cost per unit area of the radial waveguide concentrator-receiver system. Optimal design configurations that results in the minimum levelized cost of power (LCOP) are identified for thermal desalination and concentrating solar power generation applications.

Schematic of the radial waveguide configuration.
Schematic of the radial waveguide configuration.
Radial waveguide design can meet the U.S. Department of Energy SunShot cost and performance targets.


  1. A. Narayan and R. Pitchumani, “Analysis of an Air-Cooled Air Gap Membrane Distillation Module,” Desalination, 475C, 114179, 2020.
  2. K. Nithyanandam, A. Narayan and R. Pitchumani, “Analysis and Design of a Radial Waveguide Concentrator for Concentrated Solar Thermal Applications,” Energy, 151, 940–953, 2018.
  3. A. Narayan, Investigations on Air-cooled Air Gap Membrane Distillation and Radial Waveguides for Desalination,” Master’s Thesis, Advanced Materials and Technologies Laboratory, Virginia Tech, 2017.