Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

The 3D-CFD Contribution to H2 Engine Development for CV and Off-Road Application

2024-07-02
2024-01-3017
The hydrogen engine is one of the promising technologies that enables carbon-neutral mobility, especially in heavy-duty on- or off-road applications. In this paper, a methodological procedure for the design of the combustion system of a hydrogen-fueled, direct injection spark ignited commercial vehicle engine is described. In a preliminary step, the ability of the commercial 3D computational fluid dynamics (CFD) code AVL FIRE classic to reproduce the characteristics of the gas jet, introduced into a quiescent environment by a dedicated H2 injector, is established. This is based on two parts: Temporal and numerical discretization sensitivity analyses ensure that the spatial and temporal resolution of the simulations is adequate, and comparisons to a comprehensive set of experiments demonstrate the accuracy of the simulations. The measurements used for this purpose rely on the well-known schlieren technique and use helium as a safe substitute for H2.
Technical Paper

Computational Method to Determine the Cooling Airflow Utilization Ratio of Passenger Cars Considering Component Deformation

2024-07-02
2024-01-2975
In order to improve the efficiency of passenger cars, developments focus on decreasing their aerodynamic drag, part of which is caused by cooling air. Thus, car manufacturers try to seal the cooling air path to prevent leakage flows. Nevertheless, gaps between the single components of the cooling air path widen due to the deformation of components under aerodynamic load. For simulating the cooling airflow utilization ratio (CAUR), computational fluid dynamics (CFD) simulations are used, which neglect component deformation. In this paper, a computational method aiming at sufficient gap resolution and determining the CAUR of passenger cars under the consideration of component deformation is developed. Therefore, a partitioned approach of fluid structure interaction (FSI) simulations is used. The fluid field is simulated in OpenFOAM, whereas the structural simulations are conducted using Pam-Crash.
Technical Paper

Numerical Investigation of the Effect of Piston Geometry on the Performance of a Ducted Fuel Injection Engine

2024-07-02
2024-01-3024
Ducted Fuel Injection (DFI) engines have emerged as a promising technology in the pursuit of a clean and efficient combustion process. This article aims at elucidating the effect of piston geometry on the engine performance and emissions of a metal DFI engine. Three different types of pistons were investigated and the main piston design features including the piston bowl diameter, piston bowl slope angle, duct angle and the injection nozzle position were examined. To achieve the target, computational fluid dynamics (CFD) simulations were conducted coupled to a reduced chemical kinetics mechanism. Extensive validations were performed against the measured data from a conventional diesel engine. To calibrate the soot model, genetic algorithm and machine learning methods were utilized. The simulation results highlight the pivotal role played by piston bowl diameter and fuel injection angle in controlling soot emissions of a DFI engine.
Technical Paper

Influence of Intake Charge Temperature and EGR Rate on the Combustion and Emission Characteristics of Ammonia/Diesel Dual-Fuel Engine

2024-06-12
2024-37-0025
Ammonia has emerged as a promising carbon-free alternative fuel for internal combustion engines (ICE), particularly in large-bore engine applications. However, integrating ammonia into conventional engines presents challenges, prompting the exploration of innovative combustion strategies like dual-fuel combustion. Nitrous oxide (N2O) emissions have emerged as a significant obstacle to the widespread adoption of ammonia in ICE. Various studies suggest that combining exhaust gas recirculation (EGR) with adjustments in inlet temperature and diesel injection timing can effectively mitigate nitrogen oxides (NOx) emissions across diverse operating conditions in dual-fuel diesel engines.
Technical Paper

Advance simulation method for aero-acoustic vehicle design

2024-06-12
2024-01-2938
With the electrification of powertrains, the noise level inside vehicles reach high levels of silence. The dominant engine noise found in traditional vehicles is now replaced by other sources of noise such as rolling noise and aeroacoustic noise. These noises are encountered during driving on roads and highways and can cause significant fatigue during long journeys. Regarding aeroacoustic phenomena, the noise transmitted into the cabin is the result of both turbulent pressure and acoustic pressure created by the airflow. Even though it is lower in level, the acoustic pressure induces most of the noise perceived by the occupants. Its wavelength is closer to the characteristic vibration wavelengths of the glass, making its propagation more efficient through the vehicle's windows. The accurate modeling of these phenomena requires the coupling of high-frequency computational fluid dynamics (CFD) simulations and vibro-acoustic simulations.
Technical Paper

A Finite-Element-Simulation Workflow to Investigate the Aero- and Vibro-Acoustic Signature of an Enclosed Centrifugal Fan

2024-06-12
2024-01-2940
Centrifugal fans are applied in many industrial and civil applications, such as manufacturing processes and building HVAC systems. They can also be found in automotive applications. Noise-reduction mea- sures for centrifugal fans are often challenging to establish, as acous- tic performance may be considered a tertiary purchase criterion after energetic efficiency and price. Nonetheless, their versatile application raises the demand for noise control. In a low-Mach-number centrifugal fan, acoustic waves are predominantly excited by aerodynamic fluctu- ations in the flow field and transmit to the exterior via the housing and duct walls. The scientific literature documents numerous mech- anisms that cause flow-induced sound generation, even though only some are considered well-understood. Numerical simulation methods are widely used to gather spatially high-resolved insights into physical fields.
Technical Paper

CFD Analysis of Cavitation in a Flow through GERotor Pump

2024-06-01
2024-26-0449
A gerotor pump is a positive displacement pump consisting of inner and outer rotors, with 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. A gerotor pump may be subject to erosion due to cavitation. This paper details about the CFD methodology that has been used to capture cavitation bubbles which might form during the operation of gerotor pump. A full scale (3D) transient CFD model for 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. Two different approaches have been used to model this dynamic mesh analysis in the Ansys Fluent tool - one method by using the traditional UDF script and, another method by using Python automation script.
Technical Paper

Numerical Investigation of the Aerodynamic Characteristics of a Missile Geometry at Mach 4

2024-06-01
2024-26-0443
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 geometry, 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.
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

Numerical Investigation of Aerodynamic Characteristics on a Blunt Cone Model at Various Angles of Attack under Hypersonic Flow Regimes

2024-06-01
2024-26-0446
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 angle of attack where the ratio of the lift to drag force 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 angle of attack is varied from 0º to 20º. 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.
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.
Technical Paper

A Comparative Study of RANS and Machine Learning Techniques for Aerodynamic Analysis of Airfoils

2024-06-01
2024-26-0460
It is important to accurately predict the aerodynamic properties for designing applications which involves fluid flows, particularly in the aerospace industry. Traditionally, this is done through complex numerical simulations, which are computationally expensive, resource-intensive and time-consuming, making them less than ideal for iterative design processes and rapid prototyping. Machine learning, powered by vast datasets and advanced algorithms, offers an innovative approach to predict airfoil characteristics with remarkable accuracy, speed, and cost-effectiveness. Machine learning techniques have been applied to fluid dynamics and have shown promising results. In this study, machine learning model called the back-propagation neural network (BPNN) is used to predict key aerodynamic coefficients of lift and drag for airfoils.
Technical Paper

Stability of Hypersonic Boundary Layers on Flat Plates with Sharp and Blunt Leading Edges

2024-06-01
2024-26-0457
This research employs a comprehensive methodology to explore hypersonic boundary layers' stability and transition dynamics, focusing specifically on the influence of sharp and blunt leading edges. The Stanford University Unstructured (SU2) Computational Fluid Dynamics (CFD) solver is utilized 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. Further analysis is conducted using a Python code to generate input files for the Linear Stability Solver. The Linear Stability Solver analysis constitutes a crucial phase wherein the research delves into the eigenvalue spectra, identifying dominant modes and closely scrutinizing the role of the modes in the transition process within the hypersonic boundary layers.
Event

Social Media Toolkit - 2024 AeroTech®

2024-05-18
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!

Request Info - Exhibit/Sponsor - 2024 Government/Industry Meeting

2024-05-18
Annual conference government policy, regulatory makers, automotive industry neutral forum discuss US government regulation, technology, customer acceptance future vehicle design. industry event safety, emission control, fuel efficiency, automated vehicles.
Event

2024 On-Board Diagnostics Symposium-Europe

2024-05-18
The 2024 On-Board Diagnostics Symposium-Europe (OBD-EU) continues to serve as the industry’s trusted event, providing regulatory and standards updates geared towards meeting European Commission and the California Air Resources Board ground vehicle emissions regulations.
Event

On-Board Diagnostics Digital Summit – Europe

2024-05-18
The On-Board Diagnostics Symposium-Europe (OBD-EU) is the industry’s relied-upon resource for regulatory updates and standards reviews for light- and heavy-duty emissions controls.
X