Recent Advances and Research Gaps in Aeronautical and Aerospace Engineering
Dr. Volnei Tita, Ph.D. | Sep 30, 2025
This Cureus Journals blog identifies some of the recent advances and research gaps in aeronautical and aerospace engineering, with a focus on three main areas: structures and materials, aerodynamics, and propulsion. The article also highlights the importance of the document FA9550-23-S-0001, developed by the Air Force Office of Scientific Research (AFOSR – USA), and builds on the information provided in this document. Besides, it recommends reading some relevant scientific contributions published more recently.
Structure and Materials
In terms of structures and materials, new and revolutionary flight structures, including revolutionary structural concepts and unprecedented flight configurations, hybrid structures of dissimilar materials (metallic, composite, ceramic, etc.) with multi-material joints and/or interfaces under dynamic loads (and in extreme environments), and controlled-flexibility distributed-actuation smart structures should be investigated. The predictive analysis and durability prognosis of hybrid-material structures that synergistically combine the best attributes of metals, composites, and ceramics are still strategic fields in aeronautical and aerospace engineering. Multiscale modeling and prognosis, including physics-based models that quantitatively predict the material’s performance and durability of metallic and composite flight structures operating at various regimes, are approaches that need careful investigation. Modeling and prediction of the distribution of structural flaws and service-induced damage on each aircraft and at the fleet level require more attention from aerospace engineers.
In fact, structural analysis that accounts for variability due to materials, processing, fabrication, maintenance actions, and changing mission profiles must also be carried out. Besides novel and revolutionary on-board health monitoring and embedded non-destructive evaluation (NDE), new concepts should be developed to address the significant challenges in accurately predicting structural behavior. Although investigations on structural dynamics are a classic issue, nowadays, there are many gaps to be overcome. These include control of the dynamic response of extremely flexible nonlinear structures, control of unsteady energy flow in nonlinear structures during various flight conditions, and nonlinear dynamics and vibration control of thin-wall structures of functionally graded hybrid materials with internal vascular networks under extreme loading conditions.
While observing new materials, it is important to explore the design, processing, and characterization of novel composite materials to enable transformative enhancement in their performance through the understanding of the chemistry, physics, and mechanics of heterogeneously structured materials. Such materials are aimed at significantly impacting the structural design of future aircraft, space vehicles, and satellites. It is important to advance the understanding of heterogeneously structured materials and the ability to conceptualize novel materials with collective properties not achievable in monolithic ones. These include advanced materials with exceptional temperature capabilities.
Thus, new developments in the design and processing of configurationally complex materials with controlled disorders are relevant. New approaches, such as processing methodology and novel microstructural configuration by design, should also be investigated. The utilization of topological arrangements (phase distribution on nano- to micro-scale), phase transformation, coupling effects, and material texture to optimize macroscopic properties is also important. Understanding of the interface is crucial in heterogeneously structured materials. Intrinsic properties, time-dependent microstructural evolution, as well as nanomechanical and chemical interactions at the reinforcement-matrix interface, are other challenges that need to be overcome. The incorporation of coating or interphase materials to manipulate interfacial characteristics for optimal collective behavior is also challenging. Innovative concepts for incorporating additional functionalities in structural composite materials via hierarchical design and materials hybridization represent promising new directions. The functionalities may include, but are not limited to, acoustic, thermal, electrical, and electromagnetic properties. The underlying research must show synergistic interactions between functional constituents.
Researchers should also emphasize exploiting the heterogeneity and intrinsic properties of constituent materials, rather than focusing solely on device design. Computational modeling focused on predicting the behavior of topologically complex materials in harsh environments is a rapidly emerging and strategic focus area, largely because of the use of 3D-printing processes and AI. To obtain additional information in this area, it is recommended to read the scientific contributions listed below:
A Review of Modeling of Composite Structures
A Critical Review of Recent Advances in the Aerospace Materials
A Review on Bistable Composite Laminates for Aerospace Applications
Review of Monolithic Composite Laminate and Stiffened Structures in Aeronautic Applications
Advancements in Lightweight Materials for Aerospace Structures: A Comprehensive Review
Aerodynamics
There is a great interest in aerodynamic flows arising in both internal and external configurations and extending over a wide range of Reynolds numbers, considering characterization, modeling, prediction, and control of flow instabilities, turbulent flows, and aerodynamic interactions. There is also interest in the dynamic interaction between unsteady fluid motion, linear and nonlinear structural deformations, and aerodynamic control effectors for a wide range of flight regimes. It seeks to advance the fundamental understanding of complex, time-dependent flow interactions by integrating theoretical, numerical, and experimental approaches.
Flow control studies are expected to involve an approach based on a fundamental insight into flow dynamics. In cases where that insight may not exist, studies should examine fundamental flow physics to enable flow control. Another approach includes flow control efforts that integrate modeling, control theory, and advanced sensor and/or actuator technology for flow application. The field flow around high-speed vehicles strongly influences their size, weight, lift, drag, and heating loads. Therefore, research in this area is critical. It aims to lay the scientific foundation through the discovery, characterization, prediction, and understanding of critical phenomena. External and internal transitional and turbulent wall-bounded flows are also critical. Such understanding is a prerequisite to making hypersonic flight routines.
Innovative research is sought in all aspects of high Mach number (preferably M > 5), high-temperature, non-equilibrium flows, addressing key gaps such as turbulence (structure and growth, unsteady flow-field characterization, effects of micro/macro particles in the free stream, wall roughness, curvature, angle of attack, etc.); transition (initial value and eigenvalue approaches for transition prediction, stability analysis for different modes, and multimode transition); diagnostics (measurement of both the shock layer and free-stream disturbances); and flow–structure interactions under hypervelocity conditions.
Development of physics-based models for air ro-vibrational-dissociation and ro-vibrational-translational processes that can be incorporated into Computational Fluid Dynamics (CFD) solvers without incurring orders of magnitude more time to solve a given problem is a very important topic to explore. Experiments to validate the models are also relevant. These include characterization of fundamental processes occurring between non-equilibrium flows and reacting surfaces, characterization of naturally occurring atmospheric phenomenology at high altitudes relevant to high-speed aerodynamics, and energy transfer mechanisms within high enthalpy flows. To obtain additional information in this area, it is recommended to read the scientific contributions listed below:
Editorial: Recent Developments in Aerodynamics
A Review of Hypersonic Vehicle Engine Optimization
A Review of Basic Aerodynamics
Propulsion
It is well known that combustion is the primary conversion process that supplies energy for propulsion and other functions of aerospace systems such as planes, rockets, hypersonic, and unmanned aerial vehicle (UAV) systems. In these systems, the fuel combustion process occurs at highly turbulent flow conditions, governed by underlying molecular changes from high-energy states to lower ones, generating usable energy for system functions. The key turbulent combustion attributes are critical in determining operability, performance, size, and weight of such systems. The understanding of these key attributes and the quantification of the inherent rate-controlling processes provide the scientific foundation of modeling/simulation capabilities needed for the design of new generations of aerospace systems.
Based on recent progress in understanding/modeling key chemical reaction pathways in combusting fuels and in exploring key attributes of turbulent flame structure and dynamics at relevant conditions, turbulent combustion investigations currently focus on exploring, understanding, and qualifying turbulent-chemistry interactions using physical and numerical experiments. Moreover, energy conversion processes in aerospace systems involve coupled multi-physics phenomena such as chemical reactions, turbulence, radiation, flow-material interactions, etc., in a wide range of spatial and temporal scales.
Computationally efficient modeling and simulation capabilities with sufficiently low uncertainties, coupled with measured data and enhanced by artificial intelligence and machine learning, will have game-changing impacts. Together, these advances could enable new intelligent development and design tools for future aerospace systems. Such modeling/simulation capabilities may also be used to select and conduct “numerical experiments” to explore the underlying physics at conditions where physical experiments are very difficult or impossible.
Thermodynamics provides insights into energy conversion processes and builds the foundation for developing potentially game-changing energy-conversion approaches. It also establishes the foundation and framework to analyze the energy requirement and efficiency of propulsion systems and non-propulsive subsystem functions of increasingly significant energy needs. Novel, highly efficient approaches to electric propulsion, or other non-thermal, reduced-thermal, and hybrid energy conversion processes, possibly of non-equilibrium nature, should be evaluated for future propulsion and subsystems, with special focus on UAVs and robotic platforms. Multi-functional fuels such as aviation fuels from new sources with economic and security advantages, and related conversion processes, should also be investigated. It is important to understand the fundamental aspects of a coupled plasma/material system in non-equilibrium states, for a variety of potential applications, including plasma-based space propulsion systems and plasma-spacecraft interactions. The typical conditions of interest are characterized by critical phenomena in small spatial and temporal scales, which affect the behavior over a much wider range of scales.
Detailed understanding and control of non-equilibrium and multiscale effects have the potential to overcome the limitations of traditional plasma in thermodynamic equilibrium, leading to improved system designs; preventing or leveraging dynamic features such as instabilities, coherent structures, and turbulence; and realizing chemical pathways, structural changes, or electromagnetic processes for novel devices with an unprecedented level of control.
Research interest also includes the use of data-driven methods to generate dynamic databases for accurate and efficient computational predictions. For very low earth orbit, research is needed to identify and assess the suitability of new electric propulsion candidates that may use large amounts of beamed energy and the harvesting of air as a propellant. Concepts may include pulsed and/or continuous (steady-state) electric propulsion schemes, addressing challenges related to efficient collection, conditioning, ionization, and subsequent acceleration of air to produce thrust with a sufficient specific impulse to maintain orbit. The potential use of beam energy introduces the possibility of directly coupling the beamed energy into ablative thrusters or air flows for ionization to produce plasma ejections and thrust.
Another important field consists of investigating smart, functional nano-energetics for propulsion purposes. There has been tremendous progress in the synthesis and fabrication of nano-sized reactive materials. With significant advances in quantum chemistry and molecular dynamics over the last decade, along with a broader understanding of nanomaterial properties, it may now be feasible to design a priori nanostructured reactive materials tailored to desired performance objectives, including control mechanisms at both the nanoscopic and microscopic scales. Instead of being subject to uncontrolled combustion, smart nano-energetics may be activated by external electromagnetic stimuli, such as an electrical field or light. For example, it may be desirable to initiate a reaction at a particular temperature, to release a particular compound, to turn on or turn off a reaction, to have tailored ignition properties, to achieve the extinguishment of a propellant, or to accelerate or slow down a reaction with respect to time or location.
It becomes essential to consider the dynamics of combustion processes, as higher pressures lead to increased amplitudes of fluid-dynamic and thermochemical events and fluctuations, in a wider spectrum of time scales. Mathematical and experimental analyses of these dynamics at higher levels of fidelity also lead to a "big data" problem. It becomes necessary to combine and dynamically integrate multi-fidelity simulations and experimental measurements or monitoring to systematically perform modeling, analytics, statistics, and dynamic data-driven validation for chemical propulsion. The aim here is to combine both electrochemical and mechanical functionalities within a single unit, where energy storage is achieved by materials and structures that also manage mechanical stress, including peak values encountered during launch. To obtain additional information in this area, it is recommended to read the scientific contributions listed below:
A Brief Review of Diagnostics for Electrospray Propulsion
Gaps, Challenges, and Successes in Green Propulsion
Summary
Although the field of aeronautical and aerospace engineering has witnessed a paradigm shift, there still exist many opportunities and critical research gaps in structures and materials, aerodynamics, and propulsion. Scientists and engineers are diligently working on materials that combine strength, flexibility, and built-in sensing. Research teams worldwide are also investigating complex airflow and turbulence at hypersonic speeds to improve safety and efficacy, and developing next-generation propulsion systems based on AI-assisted combustion modeling. In summary, these advances in aeronautical and aerospace engineering, along with other appropriate research-driven interventions, may result in lighter, faster, safer, and as well as more efficient and ecofriendly aircraft and spacecraft designs, thus changing the future of aviation and space exploration.