About

Chris Roh is an Assistant Professor of Biological and Environmental Engineering at Cornell University. His primary research interest is to study insect’s well-adapted interactions with abiotic and biotic surroundings, focusing on fluid mechanics, entomology, comparative biomechanics, and bio-inspired engineering. Roh investigates how insects adapt morphologically and behaviorally to dynamic fluid environments, such as air and water, and applies these findings to engineering disciplines including agricultural, biomedical, and aeronautical engineering. His work explores the structural mechanics of how insects forage, evade predators, communicate, and feed in fluid environments, aiming to inspire innovative engineering designs. Roh holds a PhD in Aeronautics from the California Institute of Technology, earned in 2017, and a B.S. in Biological Engineering with Honors and Biological Sciences from Cornell University, obtained in 2012. He teaches courses on fluid dynamics and biological principles related to fluid and solid mechanics, emphasizing the physical rules governing fluid flow as a factor in evolution and biological function. His courses include Bio-Fluid Mechanics and Ecological Mechanics, where he integrates fundamental physics with modern experimental techniques to explore biological diversity through the lens of mechanics.

Research topics

• Computer Science
• Physics
• Artificial Intelligence
• Classical mechanics
• Mathematics
• Psychology
• Mathematical analysis
• Pure mathematics
• Geometry
• Meteorology
• Mechanics

Selected publications

• Multi-pathline flow visualization using PIV images

  arXiv (Cornell University) · 2026-01-12

  preprintOpen accessSenior author

  One of the oldest flow visualization techniques is through multiple pathlines generated by the movement of seeding particles spatially distributed in the flow. In the computerized era, particle images are used in quantitative measurements, such as particle image and particle tracking velocimetry (PIV and PTV). Here, we present several methods for post-processing raw particle images to generate enhanced flow visualization without a need for conducting additional experiments. Three post-processing methods will be shown: 1) controlling the exposure time, 2) color-coding temporal information, and 3) changing the frame of reference. We showcase how employing these three methods can highlight different flow features in three canonical flow cases: vortex ring, leading edge vortex, and turbulent boundary layer. In addition to the quantitative flow field, the multi-pathline visualization is expected to augment our ability to observe fluid flow from many different perspectives.

  PublisherDOI

• Downchirp Echo From a Stationary Water Surface Wave Field Accompanying Whirligig Beetle ( <i>Gyrinidae</i> )

  Integrative and Comparative Biology · 2026-01-01

  article1st authorCorresponding

  To investigate the hypothesis that the whirligig beetle utilizes a water surface-wave analog of echolocation, we analyzed the stationary capillary-gravity wave field generated during its high-speed swimming (>23 cm/s) at the air-water interface. Our wave dynamics analysis reveals that as the beetle swims past a static object, the object broadcasts a reflected wave. When the object is in the path of beetle's swimming, a single frequency signal is generated. On the other hand, an object off the swimming path reflects a time-dependent frequency that pitches down, creating a distinct downchirp signal. Furthermore, the Doppler effect shifts and widens the frequency range of the perceived signal. The echo arrives with enough time for the beetle to respond to obstacles, allowing it to detect upstream obstacles before physical contact. This suggests that this wave field has the potential to significantly extend the beetle's sensory range. When integrated with its specialized split-vision eyes, this ripple-based echolocation would complete an essential, multimodal sensory system, granting the whirligig beetle spatial awareness across all three fluid domains.

  PublisherDOI

• Lensing Capillary Waves with a Meniscus

  ArXiv.org · 2026-01-06

  articleOpen accessSenior author

  The propagation of water waves is altered when interacting with curved surfaces. Here, we consider the problem of capillary waves interacting with a 3D meniscus. We show that when capillary waves scatter off an object surrounded by a meniscus, the resulting wavefield can be drastically altered and lensing phenomena is observed. Our results are not only an important step in surface tension dominated wave interactions, but may have implications in the biological communication of surface dwelling animals.

  PublisherOA PDF

• Vortex pair simulation Matlab Code

  AIP Publishing · 2026-01-22

  otherOpen accessSenior author

  Matlab Code for simulating vortex pair.

  PublisherDOI

• <strong>A bent straw as a tool for an affordable student-safe experiment in vortex ring dynamics</strong>

  AIP Publishing · 2026-01-01

  otherOpen access

  Vortex dynamics are an important topic in fluid dynamics, explaining phenomena like drag and lift generation, jet propulsion, and corner flows. It is also often excluded from introductory or undergraduate fluid dynamics courses on account of its complexity and the inaccessibility of practical and engaging experiments. We propose an affordable student-safe experiment to generate vortex rings and study their dynamics using a bent straw and dyed water that allows students to control key parameters, can be imaged using a smartphone camera, and explains the complex physics with simple and easily measured parameters. Vortex rings were produced that parallel seminal experiments, demonstrating secondary structures and the mirroring effect. Meanwhile, non-planar and triangular jet exits were used to demonstrate asymmetric vortex rings and vortex ring inversion.

  PublisherDOI

• Vortex pair simulation Matlab Code

  AIP Publishing · 2026-01-22

  otherOpen accessSenior author

  Matlab Code for simulating vortex pair.

  PublisherDOI

• A bent straw as a tool for an affordable student-safe experiment in vortex ring dynamics

  arXiv (Cornell University) · 2026-05-08

  preprintOpen accessSenior author

  Vortex dynamics are an important topic in fluid dynamics, explaining phenomena like drag and lift generation, jet propulsion, and corner flows. It is also often excluded from introductory or undergraduate fluid dynamics courses on account of its complexity and the inaccessibility of practical and engaging experiments. We present an affordable student-safe experiment to generate vortex rings and study their dynamics using a bent straw and dyed water that allows students to control key parameters, can be imaged using a smartphone camera, and explains the complex physics with simple and easily measured parameters. Vortex rings are produced that parallel seminal experiments, demonstrating secondary structures and the mirroring effect. Meanwhile, nonplanar and triangular jet exits are used to demonstrate asymmetric vortex rings and vortex ring inversion.

  PublisherDOI

• Lensing Capillary Waves with a Meniscus

  arXiv (Cornell University) · 2026-01-06

  preprintOpen accessSenior author

  The propagation of water waves is altered when interacting with curved surfaces. Here, we consider the problem of capillary waves interacting with a 3D meniscus. We show that when capillary waves scatter off an object surrounded by a meniscus, the resulting wavefield can be drastically altered and lensing phenomena is observed. Our results are not only an important step in surface tension dominated wave interactions, but may have implications in the biological communication of surface dwelling animals.

  PublisherDOI

• <strong>A bent straw as a tool for an affordable student-safe experiment in vortex ring dynamics</strong>

  AIP Publishing · 2026-01-01

  otherOpen access

  Vortex dynamics are an important topic in fluid dynamics, explaining phenomena like drag and lift generation, jet propulsion, and corner flows. It is also often excluded from introductory or undergraduate fluid dynamics courses on account of its complexity and the inaccessibility of practical and engaging experiments. We propose an affordable student-safe experiment to generate vortex rings and study their dynamics using a bent straw and dyed water that allows students to control key parameters, can be imaged using a smartphone camera, and explains the complex physics with simple and easily measured parameters. Vortex rings were produced that parallel seminal experiments, demonstrating secondary structures and the mirroring effect. Meanwhile, non-planar and triangular jet exits were used to demonstrate asymmetric vortex rings and vortex ring inversion.

  PublisherDOI

• Multi-pathline flow visualization using PIV images

  ArXiv.org · 2026-01-12

  articleOpen accessSenior author

  One of the oldest flow visualization techniques is through multiple pathlines generated by the movement of seeding particles spatially distributed in the flow. In the computerized era, particle images are used in quantitative measurements, such as particle image and particle tracking velocimetry (PIV and PTV). Here, we present several methods for post-processing raw particle images to generate enhanced flow visualization without a need for conducting additional experiments. Three post-processing methods will be shown: 1) controlling the exposure time, 2) color-coding temporal information, and 3) changing the frame of reference. We showcase how employing these three methods can highlight different flow features in three canonical flow cases: vortex ring, leading edge vortex, and turbulent boundary layer. In addition to the quantitative flow field, the multi-pathline visualization is expected to augment our ability to observe fluid flow from many different perspectives.

  PublisherOA PDF

Frequent coauthors

• Morteza Gharib

  16 shared

• Sunghwan Jung

  Cornell University

  3 shared

• Kwang Pum Lee

  Seoul National University

  3 shared

• Daisuke Takagi

  Municipal Hirakata City Hospital

  3 shared

• Anupam Pandey

  3 shared

• Sungyon Lee

  3 shared

• Yuming Sun

  3 shared

• Jisoo Yuk

  Cornell University

  3 shared

Awards & honors

• NSF Faculty Early Career Development Award (2025)