News

ASPL has been moved to Reed-McDonald Building (RDMC) 101B.

Dr. Kim’s research group will receive a TALENT project  grant starting from October 1st, 2026.  The project title is “Statistical and Intelligent Classification of Acoustic Emission Signals Measured from Two Surrogates.”  Benjamin Minter will be supported as a Research Assistant through this project.  

Dr. Kim’s collaborative SOCOM Phase I SBIR proposal entitled “Quiet propeller blade with acoustic rainbow reflector and bio-inspired trailing comb-like structure” was selected for funding.  This project will be sponsored by Department of Defense (DoD) and collaboratively conducted with Texas High Energy Materials.  Congratulations!

Rex is selected as a winner of the Hallberg Travel Award at Noise-Con 2026 (https://noisecon2026.org/).  The award ceremony will be held at the conference.  Congratulations!

Rex Yusri et al. have published a Noise-Con 2026 conference paper entitled “Experimental and computational aeroacoustic and aerodynamic evaluations of five eVTOL propeller blades.” Rex will present this paper at the conference (https://noisecon2026.org).  Below are the list of the authors and the abstract.

 

Experimental and computational aeroacoustic and aerodynamic evaluations of five eVTOL propeller blades

Rex Yusri, Justin Schoppe, Paul Cizmas, Yong-Joe Kim

Texas A&M University

Aureliano Perez, Jr., Aureliano Perez, III, Mackinley Haas

Texas High Energy Materials, LLC

Matthew C. Robbins

United States Air Force Research Labs (AFRL/RQTE)

 

ABSTRACT

Drones generate significant noise during their operation, limiting their usage in noise-sensitive environments. This study compared four pairs of eVTOL propeller blade designs from Texas High Energy Materials, LLC against a commercial baseline to reduce noise while maintaining aerodynamic efficiency. Experimental measurements and computational simulations were used to evaluate the aeroacoustic and aerodynamic performances. Experimental data was processed to obtain spatially averaged auto-spectra and overall sound pressure levels. It was shown that one of the proprietary blades presented the quietest overall noise level, generating an overall 14.9 dBA noise reduction compared to the commercial blades with an overall level of 80.8 dBA. Comparisons between measured and simulated data showed a 3.4 – 8.8 dBA difference, with computational models consistently underpredicting dominant noise peaks at blade passing frequencies. Although these computational models are useful in optimizing the designs where relative performance improvements are only important, the dBA difference can be reduced through improved finite element mesh quality in future simulations. Aerodynamic predictions indicated that the quietest blade design was the most energy-efficient, producing the highest average lift-to-power ratio of 0.95 N/W. Finally, experimental Nearfield Acoustic Holography results suggest that simple rotating monopole models can be used to represent the propeller noise effectively.

DOI: https://doi.org/10.3397/NC_2026_0206

Dr. Kim had attended 2026 International Conference on Nonlinear Elastic Materials (ICNEM).  He gave a presentation on the compressibility measurement of cells and particles in nonlinear, acoustophoretic, microfluidic channels.

 

Title: Compressibility Measurement of Cells and Particles in Nonlinear, Acoustophoretic, Microfluidic Channels

Presenter: Yong-Joe Kim, Ph.D., Associate Professor, Director of the Acoustics and Signal Processing Laboratory, Department of Mechanical Engineering, Texas A&M University, College Station, Texas, USA.

Author 1: Han Wang, Tsinghua University

Author 2: Zhongzheng Niu, TDK InvenSense

Author 3: Arum Han, Texas A&M University

Abstract: Compressibility of particles and cells is an interesting physical property that can be utilized in label-free separation; in particular, compressibility-dependent cell separation modalities have gained significant interest since red blood cells (RBCs) and cancer cells are observed to have different compressibility compared to benign cells. Specifically, it has been known that a cancer cell with the higher metastatic potential has the higher compressibility.  However, systems capable of continuous and simultaneous label-free separation of particles and cells based on their sizes and compressibility at high throughput have been rarely investigated. Acoustophoresis-based microfluidic separation utilizes intrinsic differences in vibro-acoustic properties of target samples under nonlinear acoustic excitations, and can be achieved using simple microfluidic systems without need for cumbersome sample preparation steps. Thus, this approach has gained significant interest as the most viable label-free separation method in terms of its strong force generation, high throughput, high specificity, and low capital and operation cost.  However, the design of state-of-the-art acoustophoretic microfluidic systems has been mainly derived from a simplistic analytical acoustic model in a “static” fluid medium with uniform temperature distribution.  Therefore, it is difficult to consider the real-world effects of “moving” fluid media, viscous boundary layers, and locally elevated temperature that significantly influence the motion of particles and cells.  In this presentation, a numerical modeling method is introduced to address these deficiencies, significantly improving the predictability and specificity of the acoustophoretic separation. As an application of the numerical method, a camera with a microscope was used to record the trajectories of cancer cell motions under nonlinear acoustic excitation in a microfluidic channel.  Then, the experimental trajectories were curve fitted to the predicted ones to identify the compressibility of the cells.  The cells with the highest metastatic potential showed the highest compressibility, which is consistent with previously reported clinical observations.

Sahil Menpara has joined in ASPL as a M.S. student.  His research will focus on acoustic metamaterials.  Welcome!

Rex is graduating with Master of Science degree.  His thesis title is “Experimental and computational aeroacoustic evaluations of five eVTOL propeller blades.”  Congratulations!

Nicholas Sandoval has joined in ASPL as a Ph.D. student.  He is currently co-advised with Dr. Pablo Tarazaga.

A new project on “Acoustic Nondestructive Evaluation of Additively Manufactured Lattice Structures Based on Digital Twins” was funded by Texas A&M University System’s Nuclear Security Office (NSO) supporting the Department of Energy Nuclear Security Enterprise and National Laboratories in execution of their missions as the relate to national security and service.