Int. J. Adv. Sci. Eng. Vol.11 No.4 4666-4678 (2025) 4666 E-ISSN: 2349 5359; P-ISSN: 2454-9967 Manjula et al., International Journal of Advanced Science and Engineering www.mahendrapublications.com Influence of Heater Length and Positions on Buoyant Convection of Micropolar Fluid in an Enclosure C.Manjula 1* , V.Sivakumar 2 , S.Sivasankaran 3,4 1 Department of Mathematics, Paavai Engineering College, Namakkal, Tamil Nadu, India 2 Department of Mathematics, Arignar Anna Government Arts College, Namakkal, Tamil Nadu, India 3 Department of Mathematics, King Abdulaziz University, Jeddah, Saudi Arabia 4 Department of Mathematics, Saveetha School of Engineering, SIMATS, Chennai, India INTRODUCTION Convection is a natural mode of heat transport in which fluid motion occurs without the influence of external forces. Instead, the movement is driven by buoyancy forces arising from temperature gradients that cause variations in fluid density. The use of natural convection in engineering necessitates the solution of many heat transfer mechanism, some of which depend on the enclosure's design and others on the local temperatures. Micropolar fluids (MPF) have also attracted a lot of scientific attention such as flow of fluids having suspensions of low concentration, polymeric fluids, colloidal fluids, blood of animal’s liquid crystals, turbulent type shear flow, and lubrication and soon. Eringen [1,2] first proposed the theory on micro-polar fluids. He presented the simplest theory for structured fluids. Mansour et al., [3] investigated mixed- mode convection in a cavity with adjacent moving walls and distinct heat sources, filled with micropolar nanofluids. Their study found that the mean Nusselt number increases as the solid volume fraction of nanoparticles is enhanced. Lukaszewicz's book [4] provides an extensive review of the theory of micropolar fluids and their diverse applications. Natural convection is a primary heat transfer mechanism in numerous engineering applications and natural processes. Beyond its practical significance, natural convection continues to captivate researchers due to the intricate coupling between fluid flow and energy transport. Numerous researches published in the last few decades, worth of literature on this subject have confirmed this phenomenon. The majority of researchers involving natural mode of convection in cavities have been on temperature differences that occur in vertical direction or horizontal direction. Nevertheless, variations from the fundamental circumstances are frequently seen. Experiments on natural mode convection under conditions of local area heating were reviewed by Aydin and Yang [5]. The authors used numerical analysis to examine buoyancy convection in a square cavity. Hsu and Chen [6] quantitatively explored a micropolar fluid’s Rayleigh-Benard type convection occurring in an enclosure. The effects of the ABSTRACT: This study analyzes the convection heat transfer to a micropolar fluid in an enclosure with varied heating lengths and locations. The left wall is heated to higher temperatures, either fully or partially, while the right wall remains cooler. The heater is placed at three different positions along the left wall, and insulation is applied to the non-active areas. Using the finite volume method, the research investigates the effects of heater length, position, and material parameters, such as the Prandtl number and Rayleigh number. Results shown in graphs of Nusselt numbers, isotherms, and streamlines indicate that the mean Nusselt number decreases with increasing material parameters. Additionally, a shorter heating section enhances average heat transfer, particularly when the heater is located at the wall's lower part. KEYWORDS: Heater length; Heater position; Natural convection; Micropolar Fluid. https://doi.org/10.29294/IJASE.11.4.2025.4666-4678 ©2025 Mahendrapublications.com, All rights reserved *Corresponding Author: manjunekenkl@gmail.com Received: 10.04.2025 Accepted: 28.05.2025 Published on: 23.06.2025