Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Multi-Scale Modeling of Selective Laser Melting Process

2024-06-01
2024-26-0415
The Selective Laser Melting (SLM) process is employed in high-precision layer-by-layer Additive Manufacturing (AM) on powder bed and aims to fabricate high-quality structural components. To gain a comprehensive understanding of the process and its optimization, both modeling and simulation in conjunction with extensive experimental studies along with laser calibration studies have been attempted. Multiscale and multi-physics-based simulations have the potential to bring out a new level of insight into the complex interaction of laser melting, solidification, and defect formation in the SLM parts. SLM process encompasses various physical phenomena during the formation of metal parts, starting with laser beam incidence and heat generation, heat transfer, melt/fluid flow, phase transition, and microstructure solidification. To effectively model this Multiphysics problem, it is imperative to consider different scales and compatible boundary conditions in the simulations.
Technical Paper

Thermal Analysis of Prismatic Core Sandwich Structural Panel for Hypersonic Application

2024-06-01
2024-26-0422
Hypersonic flight vehicles have potential applications in strategic defence, space missions, and future civilian high-speed transportation systems. However, structural integration has significant challenges due to extreme aero-thermo-mechanical coupled effects. Scramjet-powered air-breathing hypersonic vehicles experience extreme heat loads induced by combustion, shock waves and viscous heat dissipation. An active cooling thermal protection system for scramjet applications has the highest potential for thermal load management, especially for long-duration flights, considering the weight penalty associated with the heavier passive thermal insulation structures. We consider the case of active cooling of scramjet engine structural walls with endothermic hydrocarbon fuel. We have developed a semi-analytical quasi-2D heat transfer model considering a prismatic core single cooling channel segment as a representative volume element (RVE) to analyse larger-scale problems.
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

On the Aero-Thermo-Structural Performance of Rectangular and Axisymmetric Scramjet Configurations

2024-06-01
2024-26-0441
Scramjet-based hypersonic airbreathers are needed for next-generation defense and space applications. Two scramjet configurations, namely, rectangular and axisymmetric, are primarily studied in the literature. However, there is no quantitative comparison of the performance metrics between these two scramjet configurations. This study investigates the aero-thermo-structural performance of rectangular and axisymmetric scramjet engines at Mach 7 and 25 km altitude. A numerical framework involving computational fluid dynamics and computational structural dynamics is established. The aero-thermo-structural loads on the scramjet flow path are estimated using RANS/FANS simulation. A finite element-based coupled thermo-structural analysis is performed to understand the thermo-structural response. Before using the numerical models for the study, CFD and CSD modules are validated with literature data.
Event

Program - 2024 AeroTech

2024-05-02
Explore AeroTech's Key Tracks, Sessions, and Presentations on hot topics in the Aerospace industry.
Event

Exhibit & Sponsor - 2025 AeroTech

2024-05-02
Secure your space! Reserve your AeroTech exhibit booth and/or sponsorship today — and take advantage of early-bird opportunities at AeroTech® 2024.
Event

AeroTech

2024-05-02
AeroTech is your passport to explore the most remarkable advancements in aerospace technology. Form supersonic aircraft to sustainable aviation and propulsion, AeroTech covers it all.
Event

Social Media Toolkit - 2024 AeroTech®

2024-05-02
Check out the topics of discussion at the 2024 AeroTech event, such as aircraft systems, advanced air mobility, manufacturing and materials, and so much more!
Event

Exhibit & Sponsor - 2025 AeroTech

2024-05-02
Secure your space! Reserve your AeroTech exhibit booth and/or sponsorship today — and take advantage of early-bird opportunities at AeroTech® 2024.
Event

Contact - AeroTech®

2024-05-02
Contact the AeroTech team for any questions around exhibiting, sponsorship, event programming, and more.
Technical Paper

Ultra-Downsizing of ICEs Based on True Atkinson Cycle Implementations. Thermodynamic Analysis and Comparison on the Indicated Fuel Conversion Efficiency of Atkinson and Classical ICE Cycles

2024-04-09
2024-01-2096
Ultra-Downsizing (UD) was introduced as an even higher level of downsizing for Internal Combustion Engines ICEs, see [2] SAE 2015-01-1252. The introduction of Ultra Downsizing (UD) aims to enhance the power, efficiency, and sustainability of ICEs while maintaining the thermal and mechanical strain within acceptable limits. The following approaches are utilized: 1 True Atkinson Cycles are implemented utilizing an asymmetrical crank mechanism called Variable Compression and Stroke Ratios (VCSR). This mechanism allows for extended expansion stroke and continuous adjustment of the Volumetric Compression Ratio (VCR). 2 Unrestricted two or more stage high-pressure turbocharging and intensive intercooling: This setup enables more complete filling of the cylinder and reduces the compression work on the piston, resulting in higher specific power and efficiency. 3 The new Load Control (LC) approach is based to continuous VCR adjustment.
Technical Paper

Performance Analysis of Fuel Cells for High Altitude Long Flight Multi-rotor Drones

2024-04-09
2024-01-2177
In recent years, the burgeoning applications of hydrogen fuel cells have ignited a growing trend in their integration within the transportation sector, with a particular focus on their potential use in multi-rotor drones. The heightened mass-based energy density of fuel cells positions them as promising alternatives to current lithium battery-powered drones, especially as the demand for extended flight durations increases. This article undertakes a comprehensive exploration, comparing the performance of lithium batteries against air-cooled fuel cells, specifically within the context of multi-rotor drones with a 3.5kW power requirement. The study reveals that, for the specified power demand, air-cooled fuel cells outperform lithium batteries, establishing them as a more efficient solution.
Standard

Test Method for the Determination of Total Acidity in Polyol Ester and Diester Gas Turbine Lubricants by Automatic Potentiometric Titration

2024-03-18
CURRENT
ARP5088C
The test method describes the procedure for determination of the total acid number (TAN) of new and degraded polyol ester and diester-based gas turbine lubricants by the potentiometric titration technique. The method was validated to cover an acidity range of 0.05 to 6.0 mg KOH g-1. The method may also be suitable for the determination of acidities outside of this range and for other classes of lubricants.
Technical Paper

Modelling and Simulation of Cooling of Heat Sink Using Alumina Nano Reinforced PCM

2024-03-05
2024-01-1913
An escalating demand for improved heat dissipation from electronic components is driven by the imperative need to eliminate the accumulated heat that gradually builds up over time. In this study, a 3-D simulation was carried out to analyze the heat distribution performance of a heat sink based on PCM/NePCM. The heat sink was subjected to varying heat fluxes ranging from 3-7 kW/m2, and its performance was evaluated over time. The findings of the computational research indicate that using PCM assists in maintaining the heat sink base's temperature within lower bounds, and leads to uniform melting within the heat sink. Further, inclusion of Alumina nano particles integration in PCM enhanced the performance of heat sink. The percentage reduction in charging time of NePCM without fins (φ = 1%, 2.5% and 5%) in comparison to the Pure-PCM (φ = 0%) is 6%, 11% and 51% respectively at 6 kW/m2 input.
Technical Paper

Investigation of Mechanical Properties and Weld nugget Characteristics of Thermoplastics by Using Friction Stir Welding with Heat Assisted Induction Coil

2024-03-05
2024-01-1943
Friction stir welding (FSW) is a method of welding that creates a weld trail by pressing a non-consumable rotating tool with a profiled pin on the adjacent surfaces while moving transversely along the welding direction. The method was initially used with metals and alloys, but more recently, thermoplastic polymers have also been included in its application. Investigations on FSW of thermoplastic polymers made of nylon and High-density polythene (HDPE) are presented here. Weld characteristics that are like those of the base materials are attempted to be achieved. Because of their unique nature and thermal conductivity, thermoplastics FSW differs from that of metals. The use of thermoplastic materials with conventional FSW procedures presents numerous difficulties and is currently ineffective. On the weld characteristics of nylon and HDPE, statistical methods were utilized to study the impact of temperature, rotational speed, and transverse speed.
Technical Paper

Geometry Simplification for Conjugate Heat Transfer of Electric Rotating Machines Using Computational Fluid Dynamics

2024-03-05
2024-01-1930
Geometry simplification is a critical step of performing conjugate heat transfer analysis utilizing computational fluid dynamics (CFD). This paper provides a standard methodology to simplify the geometry of electric rotating machines such as electrical generators and electrical motors (both air and liquid cooled). These machines are extremely complex in design and CFD plays an imperative role in their optimization. These machines are extensively deployed throughout aerospace and automotive industries where optimization of weight, volume, and performance is paramount especially given the current global transition to renewable energy sources and vehicle hybridization / electrification.
Technical Paper

Numerical Analysis of Different Injectors for Kerosene/Hydrogen-Peroxide and Ethanol Amine/Hydrogen-Peroxide for Satellite Thruster

2024-02-23
2023-01-5180
In a satellite thruster the function of injector plays a major role in controlling the combustion. This paper presents the numerical simulation of two most used injectors namely, impinging doublet, and triplet using Ansys fluent. The injectors are designed for the non-toxic, green propellants used in satellite thrusters. The present study focuses on the design and simulation of the injectors with 2 variant of green propellants i.e., Kerosene/Hydrogen-peroxide and Ethanol Amine/Hydrogen-peroxide. The objective of the study is to investigate the performance of the two injectors in terms of atomization, combustion efficiency and thrust generation. Theoretical design calculations were performed for a 20 N bi-propellant satellite thruster. A comparative study on the condensed combustion products and injector was carried out using NASA CEA Run code and Ansys fluent, respectively. The ethanol amine/hydrogen-peroxide injector showed better performance in terms of combustion efficiency.
X