Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Study of Crew Seat Impact Attenuation System for Indian Manned Space Mission

2024-06-01
2024-26-0469
The descent phase of GAGANYAAN (Indian Manned Space Mission) culminates with a crew module impacting at a predetermined site in Indian waters. During water impact, huge amount of loads are experienced by the astronauts. This demands an impact attenuation system which can attenuate the impact loads and reduce the acceleration experienced by astronauts to safe levels. Current state of the art impact attenuation systems use honeycomb core, which is passive, expendable, can only be used once (at touchdown impact) during the entire mission and does not account off-nominal impact loads. Active and reusable attenuation systems for crew module is still an unexplored territory. Three configurations of impact attenuators were selected for this study for the current GAGANYAAN crew module configuration, namely, hydraulic damper, hydro-pneumatic damper and airbag systems.
Technical Paper

Dynamic Ascent Loads Estimation of Winged Reusable Launch Vehicle: Formulation, Analysis and Post Flight Studies

2024-06-01
2024-26-0452
A structural load estimating methodology was developed for the RLV-TD HEX-01 mission, the maiden winged body technology demonstrator vehicle of ISRO. The technique characterizes atmospheric regime of flight from vehicle loads perspective and ensures adequate structural margin considering atmospheric variations and system level perturbations. Primarily the method evaluates time history of station loads considering effects of vehicle dynamics and structural flexibility. Station loads in the primary structure are determined by superposition of quasi-static aerodynamic loads, dynamic inertia loads, control surface loads and propulsion system loads based on actual physics of the system. Spatial aerodynamic distributions at various Mach numbers along the trajectory have been used in the study. Argumentation in aerodynamic loads due to vehicle flexibility is assessed through the use of spatial aerodynamic distributions.
Technical Paper

Energy Consumption in Lightweight Electric Aircraft

2024-06-01
2024-26-0403
Electric aircraft have emerged as a promising solution for sustainable aviation, aiming to reduce greenhouse gas emissions and noise pollution. Efficiently estimating and optimizing energy consumption in these aircraft is crucial for enhancing their design, operation, and overall performance. This paper presents a novel framework for analyzing and modeling energy consumption patterns in lightweight electric aircraft. A mathematical model is developed, encompassing key factors such as aircraft weight, velocity, wing area, air density, coefficient of drag, and battery efficiency. This model estimates the total energy consumption during steady-level flight, considering the power requirements for propulsion, electrical systems, and auxiliary loads. The model serves as the foundation for analyzing energy consumption patterns and optimizing the performance of lightweight electric aircraft.
Technical Paper

Analysis for Effect of Angle of Attack on Coefficient of Lift of Wing Structure

2024-06-01
2024-26-0450
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. In this study CFD analysis is performed to obtain pressure counter of wings. 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 C L /C D ratio.
Technical Paper

CFD Methodology Development to Predict Lubrication Effectiveness in Electromechanical Actuators

2024-06-01
2024-26-0466
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. To prevent backdriving, skewed roller braking devices called "no-backs" are employed to provide braking torque. These technology components are continuing to be improved with analysis driven design innovations eg. U.S. Pat. No. 8,393,568. The no-back mechanism 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 that prevents the backdriving. By controlling the friction radius and analyzing the Hertzian contact stresses, the brake can be sized for the desired duty cycle. No-backs can be configured to provide braking torque for both tensile and compressive backdriving loads.
Technical Paper

Study of Different Designs of Chevrons for Effective Noise Reduction in Jet Engines

2024-06-01
2024-26-0408
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. Extensive research has identified the engine as the primary source of noise in aircraft, prompting the implementation of chevrons within the engine nozzle. 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. Our paper aims to conduct a comparative computational analysis encompassing seven distinct chevron designs and a design without chevrons. 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.
Technical Paper

Synergized Mixed-Signal System-on-Chip (SoC) Design and Development with System Level Modelling and Simulation for Emerging Trends using MATLAB and Simulink Tools

2024-06-01
2024-26-0463
In recent decades, research based innovative system-on-chip (SoC) design has been a very important issue, due to the emerging trends and application challenges. The SoCs encompass digital, analog and mixed-signal hardware and software components and even sensors and actuators. Modelling and simulation constitute a powerful method for designing and evaluating complex systems and processes for many analysts and project managers as they engage in state of-the-art research and development. Modelling and simulations not only help them with the algorithm or concept realization and design feasibility, but it also allows experimentation, optimization, interpretation of results and validation of model.
Technical Paper

Numerical Approach for the Characterization of the Venting Process of Cylindrical Cells Under Thermal Runaway Conditions

2024-05-06
2024-01-2900
The increasing awareness on the harmful effects on the environment of traditional Internal Combustion Engines (ICE) is driving the industry toward cleaner powertrain technologies such as battery-driven Electric Vehicles. Nonetheless, the high energy density of Li-Ion batteries can cause strong exothermic reactions under certain conditions that can lead to catastrophic results, called Thermal Runaway (TR). Hence, a strong effort is being placed on understanding this phenomena and increase battery safety. Specifically, the vented gases and their ignition can cause the propagation of this phenomenon to adjancent batteries in a pack. In this work, Computational Fluid Dynamics (CFD) are employed to predict this venting process in a LG18650 cylindrical battery. The ejection of the generated gases was considered to analyze its dispersion in the surrounding volume through a Reynolds-Averaged Navier-Stokes (RANS) approach.
Technical Paper

Algorithm to Calibrate Catalytic Converter Simulation Light-Off Curve

2024-04-09
2024-01-2630
Spark ignition engines utilize catalytic converters to reform harmful exhaust gas emissions such as carbon monoxide, unburned hydrocarbons, and oxides of nitrogen into less harmful products. Aftertreatment devices require the use of expensive catalytic metals such as platinum, palladium, and rhodium. Meanwhile, tightening automotive emissions regulations globally necessitate the development of high-performance exhaust gas catalysts. So, automotive manufactures must balance maximizing catalyst performance while minimizing production costs. There are thousands of different recipes for catalytic converters, with each having a different effect on the various catalytic chemical reactions which impact the resultant tailpipe gas composition. In the development of catalytic converters, simulation models are often used to reduce the need for physical parts and testing, thus saving significant time and money.
Technical Paper

A 3-D computational fluid dynamics modeling of the churning loss and oil pattern in a single-stage gearbox

2024-04-09
2024-01-2637
Modern gearboxes are designed with three main goals in mind: load-carrying capacity, noise, vibration, and harshness (NVH) behavior, and efficiency. Efficiency is especially important because gearboxes contribute significantly to energy consumption. One way to improve efficiency is to reduce churning losses, which are caused by the movement of oil in the gearbox housing. Computational fluid dynamics (CFD) methods can be used to visualize the oil flow inside gearboxes and identify ways to reduce churning losses. The driving range of battery electric vehicles (BEVs) can be improved by designing an efficient gearbox. In this study, a Volume of Fluid Method based commercial CFD solver (SimericsMP+) is used to investigate the oil flow and churning losses in a single-stage gearbox. The model is validated against published high-speed camera recordings and measurements of the single-stage gearbox of thee FZG no-load power loss test rig.
Technical Paper

Advancements in GPU-based LBM CFD Solver for Vehicle Aerodynamics: Enhancing Early Stage Development with Sliding Mesh Rotating Reference Frame

2024-04-09
2024-01-2523
In the field of automotive aerodynamics, there's a consistent need for tools that effectively manage both rapid design changes and comprehensive simulations. The recent GPU code update to the PowerFLOW, Lattice Boltzmann simulation tool is an attempt to meet this need. An important feature of this update is the inclusion of the Sliding Mesh rotating reference frame, which improves rim modeling accuracy. This modification provides a clearer depiction of vehicle aerodynamics, aiming for balanced and efficient designs. The updated GPU solver has been tested with two main resolutions. First, a low-resolution aerodynamics scheme which can assist designers and stylists in their initial stages of design. This setup aims to offer a rapid iterative design process. In addition, for more detailed analysis, full-scale resolution simulation setups are possible with the NVIDIA A100's 80GB memory capacity.
Technical Paper

Validation of the PC-Crash Single Track Vehicle Driver Model for Simulating Motorcycle and Bicycle Motion

2024-04-09
2024-01-2475
This study describes and validates the single-track vehicle driver model used in newer versions of PC-Crash simulation software. This model eliminated several limitations that PC-Crash previously had for simulating motorcycle dynamics. Within PC-Crash, a path can be established for a motorcycle to follow. The software will generate the steering inputs and resulting motorcycle lean (roll) needed to follow the user defined path (within the limits of friction and stability) at the prescribed speed, braking, or acceleration levels. For the current study, this model was subjected to several validation tests. First, the model was examined for a simple scenario in which a motorcycle traversed a pre-defined curve at several speeds. This test resulted in the conclusion that the single-track driver model yielded motorcycle lean angles consistent with the standard, simple lean angle formula widely available in the literature.
Technical Paper

Extended Deep Learning Model to Predict the Electric Vehicle Motor Operating Point

2024-04-09
2024-01-2551
The transition from combustion engines to electric propulsion is accelerating in every coordinate of the globe. The engineers had strived hard to augment the engine performance for more than eight decades, and a similar challenge had emerged again for electric vehicles. To analyze the performance of the engine, the vector engine operating point (EOP) was defined, which was common industry practice, and the performance vector electric vehicle motor operating point (EVMOP) was not explored in the existing literature. In an analogous sense, electric vehicles are embedded with three primary components [Battery, Inverter, Motor], and in this article, the EVMOP was defined using the parameters [motor torque, motor speed, motor current]. As a second aspect of this research, deep learning models were developed to predict the EVMOP by mapping the parameters representing the dynamic state of the system in real time.
X