**5. Conclusions**

A numerical study is carried out concerning the bio-convection heat transfer of nanofluid flow near a curved stretched sheet containing gyrotactic micro-organisms. This research marks the impact of thermophoresis and Brownian motion in nanofluids that contains both nanoparticles and gyrotactic microorganisms, utilizing the well-known Buongiorno model. Two-dimensional Navier-Stokes, energy, and concentration equations are solved using the BVP4c integrated MATLAB package. The effects of various design parameters on the MHD flow and heat transfer are investigated. The following are the main observations of this study:


Many fields, including pharmacodynamics, drug delivery methods, tumor treatment, hemodynamics, biological polymer synthesis, bacteria-powered micro-mixers, bio-energy systems, pollution dispersion in aquifers, and others [43–47], could benefit from the use of the aforementioned problem. Increasing a nanofluid's stability as a suspension is another justification for including microorganisms in it. The same flagella that propel microorganisms will also cause some mixing at the micro-scale (on a scale that is similar to the size of a nanoparticle and a bacterium), which may prevent nanoparticles from aggregating and agglomerating, and also lead to the macroscopic motion of the host fluid. In this way, the relevance of bioconvection effects in the boundary layer close to the wall has been highlighted by the application of our model to nanofluid heat transfer in the laminar domain.

**Author Contributions:** Conceptualization, P.R., N.A.A., A.W., N.A.S. and Y.J.; methodology, P.R., N.A.A., A.W., N.A.S. and Y.J. software, P.R., N.A.A., A.W., N.A.S. and Y.J.; validation, P.R., N.A.A., A.W., N.A.S. and Y.J.; formal analysis, P.R., N.A.A., A.W., N.A.S. and Y.J.; investigation, P.R., N.A.A., A.W., N.A.S. and Y.J.; resources, P.R., N.A.A., A.W., N.A.S. and Y.J.; writing—original draft preparation, P.R., N.A.A., A.W., N.A.S. and Y.J.; writing—review and editing, P.R., N.A.A., A.W., N.A.S. and Y.J.; visualization, P.R., N.A.A., A.W., N.A.S. and Y.J.; supervision, P.R., N.A.A., A.W., N.A.S. and Y.J.; funding acquisition, Y.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the National Research Foundation of Korea (NRF) funded by the Korean government (MSIT) [NRF-2021R1I1A3047845, NRF-2022R1A4A3023960] and BK21 Four program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education of Korea (Center for Creative Leaders in Maritime Convergence).

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
