Aerospace

Research

19 pages, 5471 KB

Open AccessArticle

Vectoring Control of Bilateral Parallel Offset Jet: Flow Characteristics and Control Mechanism

by Nanxing Shi, Yunsong Gu, Tonghua Xu, Guangtao Liu, Chun Zhang, Yuhang Zhou and Jianglong Guo

Aerospace 2026, 13(5), 443; https://doi.org/10.3390/aerospace13050443 - 9 May 2026

Viewed by 329

Abstract

We proposed a bilateral parallel offset jet model that enables jet vectoring control without the need for an active high-pressure secondary flow. Flow characteristics, including deflection force, wall pressure distribution, and flow structures, were investigated. The evolutions of key flow structures during jet [...] Read more.

We proposed a bilateral parallel offset jet model that enables jet vectoring control without the need for an active high-pressure secondary flow. Flow characteristics, including deflection force, wall pressure distribution, and flow structures, were investigated. The evolutions of key flow structures during jet deflection were investigated, including the passive secondary flow, the shear layer, the boundary layer, and the separation bubble. By analyzing the formation, dissipation, and interactions of the key flow structures, as well as their relationship with pressure characteristics, the mechanism of the jet deflection control was further deduced. The fundamental driving force of the jet deflection stems from the unbalanced pressure difference on either side of the jet, and the valve can control the flow rate of passive secondary flow, thereby altering the near-wall pressure on its side and further generating a pressure that propels the jet to deflect. For walls of different lengths, at a moderate wall length, where L* = 1.5, with the valve controlling the passive secondary flow, a maximum jet vectoring angle of 6.4° can be continuously achieved at a low Reynolds number. Within the range where 20% < δ_v < 100%, the nonlinear error of jet vectoring control is 5.7%. At a short wall length, where L* = 0.5, the driving force generated by the valve to deflect the jet is insufficient, and the maximum vector angle is 0.3°. For longer walls, the impact of the jet against the trailing edge of the wall obstructs jet deflection; therefore, extending the wall is not conducive to jet vectoring control. Featuring a non-expanding wall structure, the bilateral parallel offset jet model provides a new thrust vectoring control scheme characterized by a compact afterbody, no need for a high-pressure secondary air source, and a simple structure. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

17 pages, 10130 KB

Open AccessArticle

Attitude Control of Over-Actuated Fixed-Wing Aircraft Based on Predefined Time Control

by Fangping Chen, Pengfei Li, Hainuo Chen, Xuebin Ni, Jingjing Pan, Tingting Guo, Limin Bai, Junying Ma and Qu Wang

Aerospace 2026, 13(3), 221; https://doi.org/10.3390/aerospace13030221 - 27 Feb 2026

Viewed by 415

Abstract

This paper presents a novel predefined-time attitude-control framework for fixed-wing aircraft with over-actuated systems, solving aerodynamic uncertainties and nonlinear couplings during high-angle-of-attack flight. The proposed methodology integrates a Predefined-Time Extended State Observer (PTESO) with a Predefined-Time Control Laws (PTCL), which ensures the convergence [...] Read more.

This paper presents a novel predefined-time attitude-control framework for fixed-wing aircraft with over-actuated systems, solving aerodynamic uncertainties and nonlinear couplings during high-angle-of-attack flight. The proposed methodology integrates a Predefined-Time Extended State Observer (PTESO) with a Predefined-Time Control Laws (PTCL), which ensures the convergence of the control system within predefined time intervals. Simulation results rigorously validate that the predefined-time parameters directly govern the convergence speed and control smoothness. Aligning with the control allocation method, the PTESO–PTCL framework thus provides an integrated control solution that enables explicit and predictable tuning of the error convergence time. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

30 pages, 1887 KB

Open AccessArticle

Energetic and Exergetic Analysis of High-Bypass Turbofan Engines for Commercial Aircraft: Part I—Operation and Performance

by Abdulrahman S. Almutairi, Hamad M. Alhajeri, Mohamed Gharib Zedan and Hamad H. Almutairi

Aerospace 2026, 13(1), 27; https://doi.org/10.3390/aerospace13010027 - 26 Dec 2025

Cited by 2 | Viewed by 1970

Abstract

Despite substantial advances in turbofan engineering, a crucial gap persists: there remains the need for an all-inclusive comparative analysis that includes real-world operational data and evaluates the performance of modern turbofans used in aviation. Specifically, systematic investigations that examine the exergy and efficiency [...] Read more.

Despite substantial advances in turbofan engineering, a crucial gap persists: there remains the need for an all-inclusive comparative analysis that includes real-world operational data and evaluates the performance of modern turbofans used in aviation. Specifically, systematic investigations that examine the exergy and efficiency of turbofan engines for takeoff and cruise remain scarce. Further, the current literature needs to address rigorous performance assessments that include simultaneous consideration of the combined effects of ambient conditions (e.g., temperature, density, relative humidity), Mach number, and turbine inlet temperature on high-bypass turbofan engines used in modern, commercial aircraft. Energetic and exergetic analyses were conducted on five commercial high-bypass turbofan engines with different configurations for both takeoff and cruise flight modes. The computational thermodynamic models developed showed strong correlation with manufacturers’ specifications. Performance evaluations included variations in ambient conditions, altitude, Mach number, and turbine inlet temperature. Results demonstrate that three-spool engine architecture exhibits 70–71% reduction in exergy destruction between flight phases compared to 62.5% for two-spool designs, indicating greater operational adaptability. The combustion chamber emerged as the dominant contributor to irreversibilities, representing approximately 55–58% of overall exergy destruction during takeoff operations. Results demonstrate that increased ambient temperature and/or humidity increase both degraded exergetic efficiency and thrust-specific fuel consumption, and that Mach number and altitude influenced efficiency metrics through ram compression and density effects, while higher turbine inlet temperatures enhanced exhaust kinetic energy via increased thermal input. We show that cruise operations demonstrated superior exergetic efficiency (68–74%) compared with takeoff (47–60%) across all engine configurations. Our results confirm the fundamental trade-off in turbofan design: for long-range applications, high-bypass engines prioritize propulsive efficiency, while for power-intensive operations, moderate-bypass configurations deliver higher specific thrust. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

45 pages, 15707 KB

Open AccessArticle

Lightweight, High-Efficiency, High-Dynamic-Response and Low-Ripple DC-DC Converters Based on Interleaved Magnetic Integrated Switched-Coupled Inductor for Electric Propulsion Aircraft

by Rui Guo, Hongkai Gao, Li Chen, Yiyi Zhang and Lei Wang

Aerospace 2025, 12(12), 1067; https://doi.org/10.3390/aerospace12121067 - 30 Nov 2025

Cited by 2 | Viewed by 745

Abstract

With the development of distributed electric propulsion aircraft, researching airborne high-efficiency, high-power-density, high-gain, high-dynamic and low-ripple, low-stress DC-DC that meets aviation standards is an urgent and profoundly challenging task (Research Background). We propose a new topology to implement related applications. The new topology [...] Read more.

With the development of distributed electric propulsion aircraft, researching airborne high-efficiency, high-power-density, high-gain, high-dynamic and low-ripple, low-stress DC-DC that meets aviation standards is an urgent and profoundly challenging task (Research Background). We propose a new topology to implement related applications. The new topology consists of an interleaved switched-inductor unit for a high-gain, low-ripple, and high-dynamic response, and a switched-capacitor unit for secondary boosting and low voltage stress. This study first analyzes in depth the operating principle and electrical characteristics of the proposed topology in different modes, showing that the proposed topology can achieve an extremely high voltage gain while maintaining low voltage stress. Moreover, the proposed topology employs interleaved inverse coupled inductors to eliminate right-half-plane zero (RHPZ). We establish a universal design guideline for coupled inductors by deriving the equivalent inductance equations, and we implement an ultra-lightweight switched-coupled inductor using planar thin-film integrated magnetic technology. We conduct small-signal modeling to verify the loop characteristics and stability of the proposed converter. Finally, the correctness of the theoretical analysis and the advantages of the proposed converter were verified through a 5000 W experimental prototype and comprehensive comparative experiments. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

25 pages, 9674 KB

Open AccessArticle

Dual-Redundancy Electric Propulsion System for Electric Helicopters Based on Extended State Observer and Master–Slave Fault-Tolerant Control

by Shuli Wang, Zhenyu Du and Qingxin Zhang

Aerospace 2025, 12(9), 847; https://doi.org/10.3390/aerospace12090847 - 19 Sep 2025

Cited by 2 | Viewed by 1243

Abstract

To improve the reliability and fault tolerance of electric helicopter propulsion systems, this paper presents a master–slave fault-tolerant control method based on an extended state observer (ESO) for dual-redundant electric propulsion systems that addresses dynamic coupling disturbances. First, the control architecture puts the [...] Read more.

To improve the reliability and fault tolerance of electric helicopter propulsion systems, this paper presents a master–slave fault-tolerant control method based on an extended state observer (ESO) for dual-redundant electric propulsion systems that addresses dynamic coupling disturbances. First, the control architecture puts the master motor in speed loop mode and puts the slave motor in torque loop mode with an ESO to estimate disturbances and compensate for mechanical coupling torque through feedforward control based on Lyapunov stability theory. Second, a least squares parameter identification method establishes a current-torque mapping model to ensure consistent dual-motor output. Then, fault-tolerant switching is implemented, transitioning from normal torque mode coordination to independent speed mode with adaptive PI adjustment during faults. Experimental validation shows that the total torque stabilizes at 240 N·m, and the synchronization error remains within ±0.5 N·m during normal operation. Under single-motor fault scenarios, the ESO detects disturbances within 15 ms with >95% accuracy. The system speed decreases to a minimum of 2280 rpm (5% deviation) and recovers within 3.5 s. Compared to traditional PI control, this method improves torque synchronization by 65.4%, speed stability by 62.6%, and dynamic response by 51.2%. Finally, the results validate that the method effectively suppresses coupling interference and meets aviation safety standards, providing reliable, fault-tolerant solutions for electric helicopter propulsion. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

35 pages, 8465 KB

Open AccessArticle

Momentum- and Energy-Based Analyses of the Aerodynamic Effects of Boundary Layer Ingestion and Propulsion–Airframe Integration on a Blended Wing Body–Turbofan Configuration

by Gang Wang, Dong Li, Peifeng Li and Binqian Zhang

Aerospace 2025, 12(9), 846; https://doi.org/10.3390/aerospace12090846 - 18 Sep 2025

Viewed by 1563

Abstract

Boundary layer ingestion (BLI) propulsion offers notable benefits for blended wing body (BWB) aircraft, and understanding the interrelated effects of BLI and propulsion–airframe integration (PAI) is critical for early-stage design decisions. This study numerically applies combined momentum- and energy-based analyses to a closely [...] Read more.

Boundary layer ingestion (BLI) propulsion offers notable benefits for blended wing body (BWB) aircraft, and understanding the interrelated effects of BLI and propulsion–airframe integration (PAI) is critical for early-stage design decisions. This study numerically applies combined momentum- and energy-based analyses to a closely coupled but non-integrated BWB–turbofan configuration enabling a continuous transition from non-BLI to BLI conditions. By introducing an idealized capture streamtube–airframe interaction force, the drag of BLI layout is decomposed into additional and external components, enabling quantification of a lift-to-drag ratio improvement of 1.7–2.6, corresponding to a 7.14–8.27% gain in power saving coefficient (PSC). Additional drag reduction, the primary contributor to total drag savings, is analytically attributed to inlet total pressure loss. The resulting decrease in required thrust under BLI shows strong mathematical correlation with jet dissipation reduction, revealing an intrinsic link between drag reduction and power saving. PAI exerts a significant influence on the BLI benefits, including nacelle cowl drag penalties, significant variations in shock wave location and strength, and notable suppression of both boundary layer and wake dissipation for the portion of cowl immersed in the airframe wake. These findings inform the transition from podded to BLI engine layouts. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

27 pages, 5047 KB

Open AccessArticle

Inertial Subrange Optimization in Eddy Dissipation Rate Estimation and Aircraft-Dependent Bumpiness Estimation

by Zhenxing Gao, Qilin Zhang and Kai Qi

Aerospace 2025, 12(4), 293; https://doi.org/10.3390/aerospace12040293 - 30 Mar 2025

Viewed by 1090

Abstract

Atmospheric turbulence leads to aircraft bumpiness. In current vertical wind-based eddy dissipation rate (EDR) estimation algorithms based on flight data, the inertial subrange is determined empirically. In application, specific aircraft bumpiness can only be described by an EDR indicator. In this study, the [...] Read more.

Atmospheric turbulence leads to aircraft bumpiness. In current vertical wind-based eddy dissipation rate (EDR) estimation algorithms based on flight data, the inertial subrange is determined empirically. In application, specific aircraft bumpiness can only be described by an EDR indicator. In this study, the objective turbulence severity and aircraft-related bumpiness estimation were explored with an optimized inertial subrange. To obtain the inertial subrange, the minimum series length to estimate EDR was determined under different flight data sampling rate. In addition, the basic series length to estimate the inertial subrange was determined according to Blackman–Tukey spectra estimation theory. In aircraft-dependent bumpiness estimation, the unsteady vortex lattice method (UVLM) was designed to obtain an accurate aircraft acceleration response to turbulence. An in situ aircraft bumpiness estimation and bumpiness prediction method were further proposed. Simulation and experiments on real flight data testified the optimized aircraft-independent EDR estimation and aircraft-dependent bumpiness estimation successively. This study can be further applied to estimate the turbulence severity on a particular airway, while the bumpiness of specific aircraft can be predicted. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Figure 1

55 pages, 960 KB

Open AccessArticle

A Systematic Approach towards the Integration of Initial Airworthiness Regulatory Requirements in Remotely Piloted Aircraft System Conceptual Design Methodologies

by Álvaro Gómez-Rodríguez, Cengiz Turkoglu and Cristina Cuerno-Rejado

Aerospace 2024, 11(9), 735; https://doi.org/10.3390/aerospace11090735 - 7 Sep 2024

Cited by 5 | Viewed by 2734

Abstract

The regulatory framework of Remotely Piloted Aircraft Systems (RPASs) has recently experienced an extraordinary evolution. This article seeks to improve the integration of certification considerations in RPAS conceptual design approaches so as to enhance the safety, certifiability and competitiveness of their resulting designs. [...] Read more.

The regulatory framework of Remotely Piloted Aircraft Systems (RPASs) has recently experienced an extraordinary evolution. This article seeks to improve the integration of certification considerations in RPAS conceptual design approaches so as to enhance the safety, certifiability and competitiveness of their resulting designs. The first part of the research conducts a two-stage analysis of contemporary regulations related to an RPAS’s initial airworthiness. In the first stage, the broad international regulation paradigm is evaluated attending to a set of criteria that are tightly related to both airworthiness and design considerations. The second stage keeps the most promising documents from a design–integration standpoint, which are assessed according to their applicability considering both design and operational aspects. The results of this analysis provide insights regarding the main issues in airworthiness design criteria extraction and integration in design methodologies. To aid the designer in surmounting these challenges, a flexible procedure named DECEX is developed. Considering the documents and findings from the survey, and attending to the scope of the design methodology being developed, it aids in establishing a complete regulatory document corpus and in comparing and extracting the applicable airworthiness design criteria. Two case studies for different RPAS types are conducted to demonstrate its application. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology (2nd Edition))

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Advanced Aircraft Technology (2nd Edition)

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (8 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI