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The Aerospace Industry's drive towards zero defects has seen a significant shift to prevent defects and improve product quality during the design phase, instead of waiting until post-production inspection to discover and troubleshoot problems. Trying to ensure zero defects during the post-production inspection phase is too late in the product life cycle because it can lead to substantial costs. Aerospace Engine Supplier Quality (AESQ) introduced the Advanced Product Quality Planning (APQP) [2] process to realize zero defects. In APQP Phase 2 [2], Product and Design Development, a key output is performing a Design Failure Modes and Effects Analysis (DFMEA). Moog has effectively implemented a DFMEA process that adeptly identifies and mitigates design risks. This work showcases Moog's successful deployment of DFMEA, exemplifying the industry best practices. This work also presents simplified and innovative interpretations of DFMEA definitions and approaches. By addressing defects during
Shah, AchintShea, RachelleSiskowski, Bruce
With regards to any aerospace mission, it is very useful to have awareness about the state of vehicle, i.e., the information about its position, velocity, attitude, rotational rates and other concerned data such as control surface deflections, landing gear touchdown, working of mechanisms and so on. The sensor data from the vehicle that is communicated to the ground can be difficult to perceive and analyze. A frame work for real-time motion simulation of an aerospace vehicle from onboard telemetry data is henceforth developed in order to improve the understanding about the current state of the mission and aid in real-time decision making if required. The telemetry data, that is transmitted through User Datagram Protocol (UDP), is received and decoded to usable format. The visualization software accepts the data in a fixed time interval and applies the required transformations in order to ensure one-to-one correspondence between actual vehicle and simulation. The transformations
Shaw, Sandeep PrasadThakur, AdarshNair, TharaKK, Raveendra
The finite element method (FEM) is one of the most robust tools in structural analysis. Typically, the input parameters in a finite element model are assumed to be deterministic. However, in practice, almost all material and geometrical properties, including the load, possess randomness. The consideration of the probabilistic nature of these quantities is essential to effectively designing a system that is robust against the uncertainties arising due to the variation in the input parameters, the significance of which has been emphasized by space agencies like NASA. Among the various techniques applicable for stochastic analysis, the perturbation method, which is based on a sound mathematical foundation derived from Taylor’s series expansion, is widely acknowledged for its much higher efficiency compared to the well-known Monte-Carlo method. With this motivation, this work presents a stochastic finite element formulation of a bar element, commonly used in aerospace structural
Dwivedi, Aakash DharMarimuthu, R
In the architecture of an Unmanned Aerial Vehicle (UAV), a crucial component responsible for the propulsion system is the electric motor. Over the years, different types of electric motors, including Brushless Direct Current (BLDC), have supported the UAV’s propulsion system in diverse configurations. However, in the context of flux flow, the Radial Flux Permanent Magnet Motor (RFPMM) has been given more priority than the Axial Flux Permanent Magnet Motor (AFPMM) due to its sustainability in design and construction. Nevertheless, the AFPMM boasts higher speed, power density, lower weight, and greater efficiency than the RFPMM, because of its shorter flux path and the absence of end-turn winding. Therefore, this paper focuses to conduct a suitability analysis of an AFPMM as a shaft-connected propeller-mounted motor, with the intention of replacing the RFPMM in UAV applications. The design of the AFPMM, incorporating topologies featuring a one-rotor, one-stator configuration, is
C, CarunaiselvaneKumar, Rajesh
Electromechanical actuators (EMAs) play a crucial role in aircraft electrification, offering advantages in terms of aircraft-level weight, rigging and reliability compared to hydraulic actuators. For various functions within the actuator such as prevention of backdriving, torque limiting, damping, braking, etc., skewed roller devices are typically employed to provide braking torque. These technology components are continuing to be improved with analysis driven design innovations e.g., U.S. Pat. No. 8,393,568. The device has the rollers skewed around their own transverse axis that allow for a combination of rolling and sliding against the stator surfaces. This friction provides the necessary braking torque. By controlling the friction radius and analyzing the Hertzian contact stresses, the device can be sized for the desired duty cycle. While operating, the rollers require sufficient lubrication to ensure local temperatures do not exceed limits of the components or the lubricant itself
Bhardwaj, DivyanshuKumar, AnantGeorge, Jubin
In the contemporary industrial landscape, machinery stands as the cornerstone of various sectors. Over time, these machines undergo wear and tear due to extensive use, leading to the introduction of subtle faults into the machine readings. Recognizing the pivotal role of machinery in diverse industries, the timely detection of these faults becomes imperative. Early fault detection is crucial for preventing costly downtimes, ensuring operational efficiency, and enhancing overall safety. This paper addresses the need for an effective condition monitoring and fault detection system, focusing specifically on the application of the Long Short-Term Memory (LSTM) deep learning model for fault detection in bearings using accelerometer data. The preprocessing phase involves extracting time domain features, encompassing normal, differentiated, integrated, and carefully selected signals, to create an informative dataset tailored for the LSTM model. This model is then meticulously trained on the
Vaishnavi, A.Sharma, AnjuNaidu, VPS
Due to their remarkable efficiency and efficacy, chevrons have emerged as a prominent subject of investigation within the Aviation Industry, primarily aimed at mitigating aircraft noise levels and achieving a quieter airborne experience. These chevrons function by inducing streamwise vortices into the shear layer, thereby augmenting the mixing process and resulting in a noteworthy reduction of low-frequency noise emissions. This paper aims to conduct a comparative computational analysis encompassing seven distinct chevron designs and one without chevrons. It also summarizes the previous works that led to the advancement of this technology. The size and configuration of the chevrons with the jet engine nacelle were designed to match the nozzle diameter of 100.48mm and 56.76mm, utilizing the advanced SolidWorks CAD modeling software. Subsequently, the computational analysis for each design was carried out using the SolidWorks Flow Simulation software. When it comes to civilian aircraft
S, Shri HariRao, Karthik M C
Indian Space Research Organisation (ISRO) uses indigenously developed launch vehicles like PSLV, GSLV, LVM3 and SSLV for placing remote sensing and communication satellites along with spacecrafts for other important scientific applications into earth bound orbits. Navigation systems present in the launch vehicle play a pivotal role in achieving the intended orbits for these spacecrafts. During the assembly of these navigation packages on the launch vehicle, it is required to measure the initial tilt of the navigation sensors for any misalignment corrections, which is given as input to the navigation software. A high precision inclinometer is required to measure these tilts with a resolution of 1 arc-second. In this regard, an indigenous inclinometer is being designed. The sensing element of this design comprises of a compliant mechanism which is designed to sense the tilt by measuring the displacement of a proof mass occurring due to the respective component of earth’s gravitational
Shaju, Tony MKrishna, NirmalRao, G NagamalleswaraKumar, T SureshK, Pradeep
Fastener joints play a critical role within aircraft engine structures by connecting vital structural members and withstanding various load scenarios, including impact occurrences like foreign object damage (FOD) on engine nacelles. The precise modeling and simulation of fastener joint behavior under dynamic loads are pivotal to ensuring their structural integrity and functionality. Simulation is essential for minimizing costly experiments in evaluating the challenging design aspect of containing FOD. Prior investigations on fastener joints have predominantly focused on quasi-static or in-plane dynamic loads. This study introduces a comprehensive methodology to simulate the impact dynamics of fastener joints, accommodating both in-plane and out-of-plane loads. The approach investigates the significance of rate-dependent and three-dimensional stress effects, including some comparative investigations using a simplified sequential stress update formulation available in LS-DYNA to
Singh, ShatrughanRoy Mahapatra, Debiprosad
The paper presents a theoretical framework for the detection and first-level preliminary identification of potential defects on aero-structure components by employing ultrasonic-guided wave-based structural health monitoring strategies, systems and tools. In particular, we focus our study on ground inspection using a laser-Doppler scan of the surface velocity field, which can also be partly reconstructed or monitored using point sensors and actuators structurally integrated. Using direct wavefield data, we first question the detectability of potential defects of unknown location, size, and detailed features. Defects could be manufacturing defects or variations, which may be acceptable from a design and qualification standpoint; however, those may cause significant background signal artefacts in differentiating structure progressive damage or sudden failure like impact-induced damage and fracture. We consider the surface velocity field over continuous time stamps obtained from laser
Kolappan Geetha, GaneshRavi, Nitin. BRoy Mahapatra, Debiprosad
Continuous improvements and innovations towards sustainability in the aviation industry has brought interest in electrified aviation. Electric aircrafts have short missions in which the temporal variability of thermal loads is high. Lithium-ion (Li-ion) batteries have emerged as prominent power source candidate for electric aircrafts and Urban Air Mobility (UAM). UAMs and Electric aircrafts have large battery packs with battery capacity ranging in hundreds or thousands of kWh. If the battery is exposed to temperatures outside the optimum range, the life and the performance of the battery reduces drastically. Hence, it is crucial to have a Thermal Management System (TMS) which would reduce the heat load on battery in addition to the cabin thermal loads. Thermal management can be done through active or passive cooling. Adding a passive cooling system like Phase Change Material (PCM) to the TMS reduces the design maximum thermal loads. However, the added weight of the PCM module may at
Nyamagoudar, VinayakP R, NamrathaBalasubrahmanyam, MadireddyVanka, SridharGattu, RaghavendraAbuheiba, AhmedJha, Rajesh Kumar
RAMBHA-LP (Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere—Langmuir Probe) was one of the key scientific payloads onboard the Indian Space Research Organization’s (ISRO) Chandrayaan-3 mission. Its objectives were to estimate the lunar plasma density and its variations near the lunar surface. The probe was initially kept in a stowed condition attached to the lander. A mechanism was designed and realized for deploying the probe at a distance of 1 meter to avoid the plasma sheath effect in the moon’s plasma environment. The RAMBHA-LP deployment system consists of a metallic spherical probe with Titanium Nitride coating on its surface, a long carbon-fiber-reinforced polymer boom, a spring-assisted deployment mechanism, a dust-protection subsystem, and a hold release mechanism (HRM) based on a shape-memory alloy-based actuator. The entire RAMBHA-LP system weighed nearly 1.3 kilograms. The system had undergone many sub-system and system-level tests in ambient, dynamic
Alam, Mohammed SabirPaul, JohnsUpadhyay, Nirbhay KumarNalluveettil, Santhosh JSateesh, GollangiA, Jothiramalingam
Lunar tubes, natural underground structures on the Moon formed by ancient volcanic activity, offer natural protection from extreme temperatures, radiation, and micro-meteorite impacts, making them prime candidates for future lunar bases. However, the exploration of lunar tubes requires a high degree of mobility. Given the Moon's gravity, which is approximately six times weaker than Earth's, efficient navigation across rugged terrains within these lava tubes is achievable through jumping. In this work, we present the design of subsystems for a miniature hexapod rover weighing 1 kg, which can walk, jump, and stow. The walking system consists of two subsystems: one for in-plane walking, employing four single-degree-of-freedom (DoF) legs utilizing the KLANN walking mechanism, and another for directional adjustments before jumping. The latter employs a novel three-DoF mechanism with the cable-pulley system to optimize space utilisation. The design of these legs prioritizes functionality
Shanbhag, Sushanth SureshSharma, ShachindraDamurothu, KrishnaSandeep, R
The design of aerospace applications necessities precise predictions of aerodynamic properties, often obtained through resource-intensive numerical simulations. These simulations, though they are accurate, but are unsuitable for iterative design processes due to their computational complexity and time-consuming nature. To address this challenge, machine learning, with its data-driven approach and advanced algorithms, offers a novel and cost-effective solution for predicting airfoil characteristics with exceptional precision and speed. This study explores the application of the Back-Propagation Neural Network (BPNN), a machine learning model, to forecast critical aerodynamic coefficients such as lift and drag for airfoils. The BPNN model is fed with input parameters including the airfoils name, flow Reynolds number, and angle of attack in relation to incoming flows. Training the BPNN model is accomplished using a dataset derived from CFD simulations employing the Spalart–Allmaras
M N, LochanN, RakshithaPrasad, B K SwathiSivasubramanian, Jayahar
The aim of this paper is to present a numerical analysis of high-speed flows over a missile geometry. The N1G missile has been selected for our study, which is subjected to a high-speed flow at Mach 4 over a range of Angle of attack (AoA) from 0° to 6°. The analysis has been conducted for a 3-dimensional missile model using ANSYS environment. The study contemplates to provide new insights into the missile aerodynamic performance which includes the coefficient of lift (CL), coefficient of drag (CD) and coefficient of moment (CM) using computational fluid dynamics (CFD). As there is a lack of availability of data for missile geometries, such as free stream conditions and/or the experimental data for a given Mach number, this paper intends to provide a detailed analysis at Mach 4. As the technology is advancing, there is a need for high-speed weapons (missiles) with a good aerodynamic performance, which intern will benefit in reduction of fuel consumption. In order to meet the
Padmanabha, M AnanthPrasad, BhoomikaSivasubramanian, Jayahar
A Gerotor pump is a positive displacement pump consisting of inner and outer rotors, with the axis of inner rotor offset from axis of outer rotor. Both rotors rotate about their respective axes. The volume between the rotors changes dynamically, due to which suction and compression occurs. Due to their high-speed rotations, a Gerotor pump may be subjected to erosion due to cavitation. This paper details about the Computational Fluid Dynamics (CFD) based methodology that has been used to capture cavitation bubbles, which might form during the operation of Gerotor pump and to identify the erosion zone which might be occur due to cavitation bubble getting burst near the surface layers of the gears. A full scale (3D) transient CFD model of a Gerotor pump has been developed using commercial CFD code ANSYS FLUENT. The most challenging part of this CFD flow modeling is to create a dynamic volume mesh that perfectly represents the dynamically changing rotor fluid volume of the Gerotor pump
Vasudevan, Dinesh BabuTuraga, Vijay Kumar
The present study discusses the determination of the Seal drag force in the application where an elastomeric seal is used with a metallic interface in the presence of different fluids. An analytical model was constructed to predict the seal drag force and an experimental test was performed to check the fidelity of the analytical model. A Design of Experiment (DoE) was utilized to perform an experimental test considering different factors affecting the Seal drag force. Statistical tools such as the Test for Equal Variances and One Way Analysis of Variance (ANOVA) were used to draw inferences for the population based on samples tested in the DoE test. It was observed that Glycol fluids lead to lubricant wash-off resulting in increased seal drag force. Additionally, non-lubricated seals tend to show higher seal drag force as compared to lubricated seals
Yarolkar, MakrandTelore, MilindPatil, Sandip
With the present state of the art technology, size and mass of the satellites have come down. This necessitated the need for a low shock separation system that does not have mass attached to the separated satellite. Development of Nano satellites with mass of the order of 1 to 24 kg has become popular among scientific/ academic institutions for carrying out scientific experiments. INLS 3U Uni-Pod System (Nano satellite dispenser system) is a satellite dispensing system designed by ISRO for accommodating four 3U class Nano satellites in a single structure where each satellite is deployed independently by separate actuation commands. INLS stands for ISRO's Nano satellite Launch System. The INLS 3U Uni-Pod separation system successfully flown in ISRO’s Launch Vehicle mission for deployment of three satellites from abroad. CubeSat separation system consists of a structure housing the satellite, Holding and release mechanism (HDRM), rattling arresting mechanism, satellite ejection mechanism
Paul, JohnsPM, Abdul SalamP, RajeevNalluveettil, Santhosh JA, Jothiramalingam
A structural load estimation methodology was developed for RLV-TD HEX-01 hypersonic experimental mission, the maiden winged body technology demonstrator vehicle of ISRO. Primarily the method evaluates time history of station loads considering effects of vehicle dynamics and structural flexibility. Station loads of critical structures are determined by superposition of quasi-static aerodynamic loads, dynamic inertia loads, control surface loads and propulsion loads based on actual physics of the system, improving upon statistical load combination approaches. The technique characterizes atmospheric regime of flight from vehicle loads perspective and ensures adequate structural margin considering atmospheric variations and system level perturbations. Features to estimate change in loads due to wind variability and atmospheric turbulence are incorporated into the load estimation methodology. Augmentation in loads due to structural flexibility is assessed along the trajectory using vehicle
Jayan, MahindPavanasam, Ashok GandhiDaniel, Sajan
Dimensional optimization has always been a time-consuming process, especially for aerodynamic bodies, requiring much tuning of dimensions and testing for each sample. Aerodynamic auxiliaries, especially wings, are design dependent on the primary model attached, as they influence the amount of lift or reduction in drag which is beneficial to the model. This study aims to reduce the time period taken to finalize the design parameter for the same. For a wing, the angle of attack is essential in creating proper splits to incoming winds, even under high velocities with larger distances from the separation point. In the case of a group of wings, each wing is then mentioned as a wing element, and each wing is strategically positioned behind the previous wing in terms of its vertical height and its self-angle of attack to create maximum lift. At the same time, its drag remains variable to its shape ultimately maximizing the CL/CD ratio. A high value of CL indicates a significant component of
Hujare, Pravin PHujare, Deepak PChoudhary, PrateekSakat, AbhishekKaranjkar, Rushil
Design of Launch vehicle is multidisciplinary process in which designers of all the domain of engineering like mechanical, electronics, chemical, materials etc contribute. For the mechanical design, Coupled Load Analysis (CLA) is statutory requirement without which no launch vehicle will be allowed to fly. In CLA, launch vehicle is subjected to various loads during its flight due to engine thrust depletion / shut-off, thrust oscillation, wind and gust, maneuvering loads. In aerospace industry a standard CLA is performed by generating the mathematical model of launch vehicle and coupling it with reduced mathematical model of payload and applying the boundary conditions. A CLA is a time consuming process as several flight instances and load cases need to be considered along with generation of structural dynamic model at each time instants. For every new mission, the payloads are mission specific whereas the launch vehicle and the loads remain unchanged. To take advantage of this fact, a
Kurudimath, KottreshJalan, Salil KanjRose, Jancy
The purpose of the Air Generation System is to provide a constant supply of conditioned fresh air to meet the necessary oxygen availability and to prevent CO2 concentrations for the occupants in an aircraft. The engine bleed energy or electrical load energy consumed towards this circumstance accounts to be approximately 5% of total fuel burn and in turn, contributes to the global emissions of greenhouse gases. This paper studies the improvement areas of the present conventional system such as fuel burn consumption associated with an aircraft ECS depending on the amount of bleed, ram air usage and electric power consumption. Improved systems for sustainability and hybridization in environmental control systems are desirable in aircraft. This paper explains how a new design of the sustainable hybrid module assists the conventional system, by using a proposed modular MPBR. The MPBR system generates oxygen-enriched air, which is mixed with the traditional fresh air generated from
Subrahmanya, ShreeshaKumar, NaveenRanjan, JayantKotnadh, Shivaprasad
In any human space flight program, safety of the crew is of utmost priority. In case of exigency in atmospheric flight, the crew is safely and quickly rescued from the launch vehicle using Crew Escape System (CES). CES is a critical part of the Human Space Flight which carries the crew module away from the ascending launch vehicle by firing its rocket motors (Pitch Motor (PM), Low altitude Escape Motor (LEM) and High altitude Escape Motor (HEM)). The structural loads experienced by the CES during the mission abort are severe as the propulsive, aerodynamic and inertial forces on the vehicle are significantly high. Since the mission abort can occur at anytime during the ascent phase of the launch vehicle, trajectory profiles are generated for abort at every one second interval of ascent flight period considering several combinations of dispersions on various propulsive parameters of abort motors and aero parameters. Depending on the time of abort, the ignition delay of PM, LEM and HEM
S, SubashBabu P, GirishDaniel, Sajan
This research employs a comprehensive methodology to explore the stability and transition dynamics of hypersonic boundary layers, focusing specifically on the influence of sharp and blunt leading edges. The Stanford University Unstructured (SU2) Computational Fluid Dynamics (CFD) solver is utilised to compute the mean flow over a flat plate, establishing a foundational basis for subsequent stability analysis. The extracted boundary layer profiles undergo validation against existing literature, ensuring accuracy and reliability. The linear stability Solver analysis constitutes a crucial phase wherein the research focuses on the eigenvalue spectra, identifying dominant modes and closely scrutinising the transition process within the hypersonic boundary layers. This investigation into stability characteristics is paramount for designing and optimising hypersonic vehicles, providing valuable insights to enhance their efficiency and security. By comprehending the intricate interplay between
Mehta, Urvi SanjivSivasubramanian, Jayahar
The study of aerodynamic forces in hypersonic environments is important to ensure the safety and proper functioning of aerospace vehicles. These forces vary with the angle of attack (AOA) and there exists an optimum AOA where the lift to drag force ratio is maximum. In this paper, computational analysis has been performed on a blunt cone model to study the aerodynamic characteristics when hypersonic flow is allowed to pass through the model. The flow has a Mach number of 8.44 and the AOA is varied from 0° to 20°. The commercial CFD solver ANSYS FLUENT is used for the computational analysis and the mesh is generated using the ICEM CFD module of ANSYS. Air is selected as the working fluid. The simulation is carried out for a time duration of 1.2 ms where it reaches a steady state and the lift and drag forces and coefficients are estimated. The pressure, temperature, and velocity contours at different angles of attack are also observed. It is found that the lift-to-drag ratio increases
Deka, SushmitaKamal, AbhishekPatra, SanjuktaSahoo, Niranjan