Thermal and structural evaluations of natural fiber composites for UAV Microjet engine nozzles

• This work proposed unique natural fiber reinforced polymer (NFRP) composites for low thermal working environments based UAV's jet engine nozzles. • Two good NFRP composites such as Jute NFRP and Hemp NFRP are experimentally tested and so the computationally investigated through advanced coupled schemes. • The Jute NFRP exhibits a significant reduction in thermal heat flux, with a rate of 99.015 %, as well as a notable decrease in equivalent thermal stress, with a reduction rate of 95.11 %, compared to traditional imposed materials. • When compared to conventionally imposed materials, Hemp NFRP shows a 99.2 percent reduction in thermal heat flux and a 98.1 percent reduction in equivalent thermal stress. • Reduced heat loss and increased exhaust efficiency are possible because to the suggested low heat flux based NFRPs. Nozzles made from NFRPs have a longer lifespan than those made from more traditional materials because of their superior thermo-structural stability. Natural fiber-reinforced polymers (NFRP) possess an advantage over conventional alloys and composites in terms of heat flux effect and corresponding heat transfer and efficiency. Hence, this study investigates the thermal and structural performance of NFRPs for use in unmanned aerial vehicle microjet engine nozzles. The primary goal is to measure the nozzle's heat flux effect based on the thermal energy sustainability characteristics on the microjet engines for various alloys, composites and NFRPs. An advanced experiment evaluates test setups for thermo-structural integrity and temperature variations for NFRPs. For this study, Jute and hemp NFRPs are computationally evaluated for thermal conductivity, heat flux reduction, and mechanical stability. Once the material properties are obtained and related outcomes are analyzed, the same is tested experimentally. The designed nozzle is examined through fluid-thermal coupling method and the implemented method is validated for proposed material studies. Outcomes like effects of heat flux, thermal strain and corresponding deformation are noted. From the obtained outcomes, compared to traditional materials like stainless steel and titanium alloys, NFRPs demonstrated a significant reduction in heat flux as high as 99.19 % and a highly reduced thermal stress of 98.18 %. Additionally, with a marginal deformation of 0.07 mm, Jute is identified to be optimum for such thermal applications. These findings highlight the potential of lightweight, sustainable materials for aerospace applications, offering improved efficiency and reduced environmental impact.