Aims Mechanical engineering is a branch of engineering science that combines the principles of physics and engineering mathematics with materials science to design, analyze, manufacture, and maintain mechanical systems (mechanics, energy, materials, manufacturing) in solving complex engineering problems. Therefore, this journal accommodates all research documentation and reports on technology applications in society and industry from various technology readiness levels (TRL): basic, applied, and report of technology application. Basic - theoretical concepts of natural science, application of engineering mathematics, special and unique materials science, theoretical principles of engineering design, production, energy conversion, or industrial mechatronics/automation that support mechanical engineering analysis with a sustainable engineering perspective. Applied - thermal-mechanical design (energy, applied mechanics, material selection, material strength analysis) to support sustainable design and engineering capabilities. Report of technology application - the impact of technology on economic and social, ecological principles, sustainability principles (sustainability), communication techniques, and factual knowledge that contribute to solving complex and sustainable engineering problems. Scope Aerodynamics and Fluid Mechanics This scope includes boundary layer control, computational fluid dynamics for engineering design and analysis; turbo engines; aerodynamics in vehicles, trains, planes, ships, and micro flying objects; flow and induction systems; numerical analysis of heat exchangers; design of thermal systems; Wind tunnel experiments; Flow visualization; and all the unique topics related to aerodynamics, mechanics and fluid dynamics, and thermal systems. Combustion and Energy Systems This scope includes the combustion of alternative fuels; low-temperature combustion; combustion of solid particles for hydrogen production; combustion efficiency; thermal energy storage system; porous media; optimization of heat transfer devices; shock wave fundamental propagation mechanism; detonation and explosion; hypersonic aerodynamic computational modeling; high-speed propulsion; thermo-acoustic; low-noise combustion; and all the unique topics related to combustion and energy systems. Design and Manufacturing This scope includes computational synthesis; optimal design methodology; biomimetic design; high-speed product processing; laser-assisted machining; metal plating, micro-machining; studies on the effects of wear and tear; fretting; abrasion; thermoelastic. This scope also includes productivity and cycle time improvements for manufacturing activities; production planning; concurrent engineering; design with remote partners, change management; and involvement of the Industry 4.0 main area in planning, production, and maintenance activities. Dynamics and Control The dynamics and control group includes aerospace systems; autonomous vehicles; biomechanics dynamics; plate and shell dynamics; style control; mechatronics; multibody system; nonlinear dynamics; robotics; space system; mechanical vibration; and all the unique topics related to engine dynamics and control. Materials and Structures The scope of this field includes composite fabrication processes; high-performance composites for automotive, construction, sports equipment, and hospital equipment; natural materials; special materials for energy sensing and harvesting; nanocomposites and micromechanics; the process of modeling and developing nanocomposite polymers; metal alloys; energy efficiency in welding and joining materials; vibration-resistant structure; lightweight-strong design; and all the unique topics related to materials and construction. Vibrations, Acoustics, and Fluid-Structure Interaction This group includes nonlinear vibrations; nonlinear dynamics of lean structures; fluid-structure interactions; nonlinear rotor dynamics; bladed disc; flow-induced vibration; thermoacoustic; biomechanics applications; and all the unique topics related to vibrations, acoustics, and fluid-structure interaction.