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The purpose of this document is to provide a template and guidance for the preparation of an SAE International technical paper. This template is comprised of the entire document “How to Write a Technical Paper” so that authors have all information where needed. You can use this template by removing all the content, text, and other information and then can use the “Styles” available in MS Word®. The main styles used are Heading 1, Heading 2, Heading 3, List Ordered Numeric (for numbered lists), List Unordered (for bullet lists), Normal (for the body of the text), Figure (for figure captions), Title (for Table titles), and Normal Table (for table body). To use the Styles feature, you can highlight the copy, select the drop-down beside Styles, and select which style you want. Alternatively, you can select the correct Style first and then begin typing. SAE International does not restrict the number of pages for a technical paper, although the recommended length is 9-12 pages in a 2-column
Turaga, Vijay KumarAadi Gopalakrishna, PradeepVasudevan, Dinesh Babu
Trajectory optimization for reusable launch vehicles is a critical challenge in space mission design, aiming to determine fuel-efficient paths for spacecraft during ascent, hover, and descent phases. Minimizing fuel consumption not only enhances cost-effectiveness but also improves mission sustainability. The optimization process is governed by nonlinear orbital mechanics, gravitational perturbations, atmospheric drag, and operational constraints such as thrust limits and collision avoidance. These factors make the problem highly non-convex and discontinuous, posing significant difficulties for classical gradient-based approaches, which often fail to identify global optima. In this work, we formulate the trajectory optimization problem for a reusable rocket executing an ascent–hover–descent cycle. The vehicle must ascend to a specified target altitude, maintain a stable hover for a given duration, and then return to the launch site. The primary decision variable is the throttle control
Eswara Sai Kumar, KandulaSingh, UtkarshPohankar, PritamA, AnoopMaharana, PriyabrataLineswala, Rut
Model-based development (MBD) and Model-based Testing are critical for airborne software compliance with DO-178C and its supplement DO-331, which specifically addresses model-based approaches for software levels A through D. Traditional manual methods increase the documentation and validation burden, leading to inconsistent implementations across the project, and raise the risk of missed defects or gaps in compliance. This paper presents an automation framework designed to align with DO-331 objectives by leveraging fine-tuned large language models (LLM) to automate the generation of high-level textual requirements and low-level model-based requirements. From these, comprehensive test cases are automatically derived, covering normal, edge, mutation based, and dynamic scenarios to ensure a thorough validation of model behavior. Utilizing AI agent, the framework extracts requirements and key parameters from documentation, enabling automated specification analysis and test script
Lalchandani, TusharPurushothaman, KalaivaniJeppu, YoganandaVijaya Kumar, Shree HarshaNatarajan, Akilandeswari
Aerospace products operate within highly complex, safety-critical environments and endure extended lifecycles, often spanning decades. Sustaining their operational value requires rigorous management of Safety, Reliability, and Availability (SRA), while global Environmental, Social, and Governance (ESG) mandates demand parallel progress toward sustainability goals. This paper introduces an AI-driven strategy that integrates these dual imperatives—Sustenance Management and Sustainability Management—within a unified Product Lifecycle (PLC) framework. The proposed approach leverages Artificial Intelligence across five PLC phases: Generative Design, Detailed Design & Verification, Manufacturing & Industrialization, Operations & Maintenance, and End-of-Life Circularity. Anchored by a certified Digital Thread, this framework ensures seamless, auditable data flow from concept to disposal. Using Life-Limiting Parts (LLPs)—such as high-stress turbine discs—as a case study, the paper demonstrates
Srinivasan, KarthikG.V.V., Ravi KumarVaderahobli, Devaraja HollaBhate, UjwalVeluri, Sastry
To develop magnesium matrix composites, ceramic silicon nitride (Si3N4) particles are added to the magnesium (AZ31) matrix at 2 wt.%. The composite is produced via disintegrated melt deposition vacuum-stir-casting procedure. Microstructural studies reveal the presence of Si3N4 particles and their uniform spreading. An L9 orthogonal array, planned using Taguchi’s experimental design, is selected for three wear parameters; axial load (AL), rotational speed (RS), and time duration (TD) with trials as per the G99 standard in the pin-on-disc apparatus to assess the wear resilient of the composite. Experimental results show an increase in axial stress, and wear loss (WL) increases dramatically. Because the area of contact shrinks as RS increases, WL diminishes dramatically. When the AL is low, the friction coefficient (CoF) increases, and when the AL is large, CoF drops. When the RS is increased, CoF decreases. To optimize multiple responses effectively, the TOPSIS (Technique for Order
Senthilkumar, N.Dhinakar Raj, C K
Submarine-launched missiles with domed nose cones are highly vulnerable to cavitation erosion as they travel at high speed through an underwater launch tube and then into the air from the sea surface. The collapse of vapour cavities crystallizes intense damage on the vehicle surfaces so that the vehicle structure and aerodynamic performance are threatened. In this work, we show the full 3D numerical and analytical analysis of surface protection concepts for the reduction of cavitation damage on such an axisymmetric dome-shaped body. A computational methodology was developed by importing a complex computer-aided design (CAD) model of a dome and the connecting tubular structure into a high-fidelity simulation environment. The geometry was simplified by omitting non-essential details to facilitate the generation of quality mesh for CFD analysis. Simulations have been carried out to analyze the flow field and pressure distribution under two critical stages, at two angles of attack of 0
Velayudhan, GauthamP S, PremkumarS, Suhail AhmedP, KrishnakumarVasantharaj, C
The increasing demand for safety and reliability in aerospace applications necessitates rigorous testing of aircraft components, including light units, for explosion proofness. Traditional explosion proofness tests are destructive, expensive, and time-consuming, requiring significant resources for test setups and prototypes. To address these challenges, this research presents a numerical methodology using Computational Fluid Dynamics (CFD) simulations to investigate the explosion proofness for aircraft light units. The primary motivation of this study is to establish a computational framework that supports early-stage design screening, reduces the number of physical prototypes, and enhances understanding of explosion behavior before formal qualification testing. This work contributes to advancing engineering practices in the aerospace industry by demonstrating the efficacy of CFD simulations in evaluating and enhancing the explosion proofness of light units. The proposed CFD model
Selvaraj, SugumaranNataraja, Prabhu
Pilot fatigue represents a critical concern in aviation safety, as it can significantly impair cognitive functions, decision-making abilities, and reaction times. In addition to decreasing performance, in-flight chronic fatigue has negative long-term health effects. Possible causes of fatigue include sleep loss, extended time awake, circadian phase irregularities and workload. Conventionally, the risk due to fatigue in aerospace is reduced by flight time limits and controlled rest requirements. Despite regulations limiting flight time and enabling optimal rostering, fatigue cannot be prevented completely. Hence, there is need to detect pilot fatigue in real time. There is ongoing research to detect pilot fatigue using devices that can capture Electroencephalogram (EEG) and Electrocardiogram (ECG). Though these devices have high fidelity, they are intrusive and can limit pilot activity. This limitation could potentially be overcome by non-intrusive devices such as a smart watch/wrist
Nyamagoudar, VinayakP R, NamrathaRamachandran, Venkataramani
This study presents a data-driven approach for strengthening aviation safety by integrating human factors assessment with modern predictive modeling techniques. The work focuses on understanding how human performance, operational conditions, and system-level interactions collectively influence safety risk, and how these interactions can be quantified to support improved design and decision-making. Unlike previous studies that address human factors or predictive modeling in isolation, this research offers a unified framework that links causal human factors indicators with statistical modeling, feature extraction, and machine learning based risk estimation. The novelty of this work lies in the structured pipeline that transforms raw categorical and narrative human factors information into measurable predictors that can be analyzed using structural modeling and machine learning. The methodology includes data preparation, dimensionality reduction, latent pattern discovery, dependence
Valiyaparambil, Praveen
Modern aircraft depend on extensive electrical wiring networks for power distribution, avionics, and control systems; however, these wiring systems are vulnerable to wear, insulation degradation, and arcing over time, leading to safety risks and costly unscheduled maintenance. This paper introduces an advanced Electric Health-Monitoring Wiring (E-Wiring) system that integrates temperature, current, insulation, vibration, and environmental sensors directly into aircraft wiring harnesses to enable continuous monitoring and intelligent fault detection. Data from these embedded sensors are processed through a distributed edge AI network, forming an Electrical Health Monitoring System (EHMS) capable of real-time diagnostics, predictive maintenance, and fault localization. The architecture comprises smart cable segments with sensor nodes, local harness gateways for edge processing, aircraft-level EHMS integration via AFDX/Ethernet, and cockpit or maintenance displays linked to ground-based
Tammana, Bala Sai Sri RohitMurthy, HarshaMendu, HarikaSivaniSunandha
Unscheduled maintenance due to the failure of critical components, such as aero-engine rolling element bearings, is a leading cause of costly Aircraft-on-Ground (AOG) events; consequently, current time-based maintenance practices are inefficient and prone to risk. This paper develops a resource-efficient Hybrid Digital Twin (HDT) model for an engine bearing, focusing on the dynamic prediction of spall growth due to Rolling Contact Fatigue (RCF), thereby enabling a condition-based maintenance paradigm. The HDT architecture integrates two core models: (1) a physics-informed model that uses established life and fatigue theory to define initial degradation thresholds, and (2) a data-driven Recurrent Neural Network (RNN), specifically a Long Short-Term Memory (LSTM) network, for dynamic degradation rate modeling. The methodology utilizes a Monte Carlo simulation coupled with RCF progression equations to generate a large, high-fidelity synthetic run-to-failure dataset under varying
Mohamed, Abbas
The aviation industry contributes to around 2% of global carbon dioxide emissions. As various sectors of the economy look to reduce their global carbon footprint, the aviation industry is positively acknowledging alternatives to jet fuel. Hydrogen proves to be one such alternative having a high energy density and producing zero carbon emissions on combustion. Hydrogen when used in a jet engine produces water vapour and NOx emissions. In order to reduce the effect of GHGs, the current study aims to develop aircraft concepts suitable with hydrogen propulsion through fuel cells for a short-haul commercial mission profile. Aircrafts such as Metro-23 and Dornier 228-212 were referenced for the requirements of a utility turboprop aircraft. The weight estimation was done to obtain the take-off weight of 10,863 kg following the optimization of thrust to weight ratio and wing loading to calculate the initial dimensions. OpenVSP was used to model the initial structure of the aircraft. For the
Bhattacharya, AnishaSeetha Ramu, Sree ValliC N, Lakshmi ManasaRohit, Benjamin
Aircraft Maintenance, Repair, and Overhaul (MRO) operations are highly complex, involving coordination among multiple stakeholders including airlines, MRO providers, OEMs, and regulatory authorities. A significant challenge in this space is managing unplanned events such as Aircraft on Ground (AOG) conditions, where delays can lead to major financial losses to airlines and safety risks. Engineers must quickly diagnose the damage, evaluate compliance against regulatory limits, coordinate with OEMs, and make critical decisions—all while navigating a fragmented ecosystem of disconnected systems, diverse document types, and time-sensitive processes. This paper presents a real-world, intelligent MRO solution that addresses these challenges through the use of Agentic AI and context engineering. The system is designed to automate and augment key MRO workflows such as damage detection, repair pathway selection, compliance verification, and supplier coordination. At its core, the solution is
Abburu, SunithaG.V.V., Ravi KumarPoovalingam, SundaresanVaderahobli, Devaraja Holla
This paper investigates the energy consumption characteristics of series hybrid aircraft with a focus on comparing conventional energy management approaches against an AI-powered optimization framework. The study comprehensively models the energy demands of a series hybrid aircraft across all major flight phases, including Idle & Ground Operations, Taxi, Takeoff, Climb, Cruise, Descent, Approach, Landing, and Rollout & Taxi. For each phase, detailed mathematical formulations are developed to capture power requirements and energy flow, incorporating real-time operational parameters to enhance the accuracy of the energy consumption estimations measured in kilowatt-hours (kWh). The AI-based optimization leverages advanced control strategies, specifically Model Predictive Control (MPC) and Reinforcement Learning (RL) algorithms, to dynamically manage the aircraft’s energy systems. MPC is employed to predict and optimize future energy usage by solving constrained optimization problems over
Kanchagar, Amogha
Initial weight estimation from Top Level Aircraft Requirements (TLAR) is a critical first step in aircraft design, yet existing empirical methods are inadequate for novel configurations such as those using Liquid Hydrogen (LH2) or Sustainable Aviation Fuels (SAF). This paper presents a hybrid methodology for top-level weight estimation of such unconventional aircraft. The approach is based on modifying a conventional baseline aircraft, integrating a new statistical model with component-specific weight estimations. A multivariate regression model to estimate the empty weight fraction (We/W0) was developed from a dataset of 44 conventional aircraft, yielding an R-squared value of 0.833. This statistical model was integrated with physics-based models for novel components, including cryogenic fuel tanks and fuel systems. The methodology accounts for iterative changes to fuselage structure and parasitic drag. Four configurations were analyzed: fuel types being Jet A1, SAF, LH2 with aft
Goyal, Tushar
It is a general practice to test aero engines to evaluate their performance in specially designed indoor test facilities after assembly, repaired or overhaul. Acoustic features are provided in the test facility to attenuate the noise level to a comfortable and acceptable level. Design of these features specially air intake and exhaust silencers are a challenging task in a flow field like aero-engine test facility considering the very high sound pressure level generated by them during test containing a very wide frequency band. Moreover, growing population and location of these facilities in the vicinity of residential areas has added this challenge in multifold. Also, the capital investment in building these facilities is huge due to their large size and longer construction time. Hence, the correct execution at first shot including design, fabrication and commissioning is very important. An attempt has been made to reduce design errors or improve the accuracy in the design stage by
Gouda, Bansidhar
The present paper reports preliminary requirement elicitation for Urban Air Mobility (UAM) from Indian perspective. A mission based approach has been adopted to identify the stakeholders and their respective requirements during different phases of the mission profile. Non adherence to the requirements emerge as possible risks for the mission and need mitigation planning. Three UAM operations for Bengaluru city viz. cargo delivery, organ delivery and passenger transport using UAM vehicle are elaborated. Stakeholders for these missions are identified and associated requirements are reported. For the cargo delivery mission, a detailed analysis is carried out to emphasis on how the India specific statutory restrictions of abiding by the red zone restrictions levied by DGCA impacts the de-tour factor and flight time. A qualitative assessment of the impact of these mission based requirements on the UAM vehicle design is presented.
DE, Manabendra M.Hebbar, ArchanaHenry, Devanandham
Dynamic responses at critical locations of a spacecraft due to excitations expected during the ascent phase of a launch vehicle mission are usually estimated through a Coupled Loads Analysis (CLA) using the structural dynamic finite element model of the launch vehicle coupled with that of the spacecraft. Generally, the full physical structural dynamic model of a spacecraft has lakhs of degrees-of-freedom (DOFs). Coupling such a model with a similar model for the launch vehicle results in exorbitantly high computational costs for CLA. Hence, dynamic analysis of such large and complex structural assemblies usually employ sub-structure coupling or Component Mode Synthesis (CMS) methods. The most widely used CMS method for dynamic analyses is the Craig-Bampton (CB) method. Conventionally, a full launch vehicle CLA involves one level of CB-reduction wherein a reduced-order dynamic model of the spacecraft is first generated using the fixed-interface CB-method. This reduced-order model is
Ramachandran, Nirmal
Polymeric optical materials such as Cyclo Olefin Polymer (COP) are adopted in aerospace lighting systems due to their excellent optical clarity, dimensional stability, moldability and weight saving advantages over glass. However, their relatively low toughness and the presence of residual molding stress make them prone to crack initiation during mechanical fastening. During its installation, crack formation was consistently observed around self-tapping screw interfaces, raising concerns over reliability, maintainability, and compliance with durability requirements. A structured Design of Experiments (DOE) was performed to identify root causes and evaluate potential mitigation methods. The investigation revealed that residual stresses in the COP material, combined with localized stress concentrations during screw tightening, were the primary drivers of crack initiation. Two complementary process improvements were identified and validated as part of mitigation plan: (i) annealing of the
S, NikhilSingh, Abhimanyu KumarKatageri, PraveenSP, PradeepChandra, Praveen
Worldwide, engineers are exploring the possibility of using polymer composites in their quest for lightweight materials. In this study, injection moulding was used to develop a biodegradable polymer PLA composite containing 20 wt.% vetiver fibers (VFs) and 2 wt.% nano-silica (nSiO2) obtained from pearl millet, which is sustainable. Materials need machining as secondary operation that required joining. Desirability analysis was used to examine and optimize machining (drilling) studies that were designed with Taguchi's design (L9 orthogonal array). Surface roughness (SR) and delamination factor (Fd) were taken as outputs, while spindle speed (SS), feed rate (FR), and drill diameter (DD) were the inputs. Drilling studies were performed on a single vertical machining center (VMC). ANOVA identifies that the FR had the most decisive influence on SR (F=559.24, p=0.001785), followed by DD and SS. FR is the dominant contributor to Fd (F=379, p=0.00263), followed by SS and DD. At low SS and high
Senthilkumar, N.
Commercial and military aircraft increasingly rely on Integrated Vehicle Health Management (IVHM) as a critical enabler for predictive maintenance, operational efficiency, and mission availability. The evolution of IVHM data communication architecture- from legacy wire-based networks to more wireless based architecture involving onboard wireless sensor networks (WSN) and IP-based air to ground communication networks introduces multidomain cyber-physical attack surfaces that challenge both functional safety and continued airworthiness. DO-326A/ED-202A and DO-356A/ED-203A standards define aviation cybersecurity requirements within a safety-driven assurance context, and IEC 62443 standard offers a defense-in-depth, lifecycle-based control framework for industrial systems. A unified approach by mapping and harmonizing the complimentary aspects of these two standards has the potential to simplify and expedite the security assurance and certification process for the IVHM and other digital
Samudrala, RamakrishnaRamamurthy, Prasanna
For brake and clutch components of aircraft vehicles which require higher mechanical strength and wear resilient, light-weight aluminium composites were developed infusing solid lubricant. In this study, hybrid composites were developed using powder metallurgy route with aluminum alloy AA356 and various amounts of zirconium oxide (ZrO2) (0, 5, 10, 15, and 20 wt.%) as reinforcements. A solid lubricant hexagonal boron nitride (hBN) at a fixed 5 wt.% is considered. Following the appropriate ASTM guidelines, the specimens were mechanically characterized by measuring their density, porosity, micro-hardness, compression strength, impact strength, and flexural strength, among other properties. The findings showed that the composites' mechanical and physical behaviour were greatly affected by the inclusion of ZrO2. Porosity increased as a result of particle clustering and interfacial voids, while density increased gradually as ceramic content increased. Consistently increasing ZrO2 addition
Senthilkumar, N.
Global Navigation Satellite System (GNSS) receivers are widely being used in aerospace as well as automotive applications primarily for navigation applications. ISRO uses indigenously developed GNSS receivers in its Launch vehicles (LV) mainly for POD (Preliminary Orbit Determination) and for INS aiding in long duration missions. Advanced GNSS receivers are being developed and used in ISRO’s new generation launch vehicles for closed loop guidance (CLG) applications. Being used in CLG, continuous solution availability and robustness of GNSS solutions are of paramount importance. From April 2023 onwards, GNSS receivers on-board ISRO’s LV missions have shown degraded performance in terms of reduction in no. of satellites tracked and in some cases loss of GNSS solution as well. This was seen in multiple missions and was analyzed in detail. It was observed that there is nearly 3-4dB reduction in carrier to noise density (C/No) ratio and corresponding change in RF AGC gain is also observed
A, Mohammed BasimO T, Anand ShankaraV S, BijuV Gopal, BijuV S, VinojK, BalanC, Radhakrishna Pillai
The development of lightweight materials for use in aerospace and automotive applications is extremely significant. Magnesium (Mg)-based alloys and composites are good candidate materials from the perspective of low density, good specific strength, and abundance. The Mg-4Zn alloy is one such alloy, which is a lightweight, biocompatible, and eco-friendly Mg-based alloy. In spite of these advantages, there is a strong need and scope to improve its wear resistance and mechanical properties. Mg-4Zn nanocomposites with Si3N4 reinforcements (a biocompatible bioceramic) are hypothesized to possess superior properties. Microstructural analysis of the vacuum stir-cast nanocomposites confirms grain refinement and a consequent increase in microhardness with an increase in Si3N4 reinforcement wt.%. The addition of Si3N4 reinforcement to improve the properties of the Mg-4Zn alloy could introduce challenges in machining. To make products from the nanocomposites, machining them with minimal
N, AnandShaju, Tony MG, Nagamalleswara RaoD, BijulalK, Jayaprakash ReddyK, VijayanChaman, Joji J