Refine Your Search

Search Results

Technical Paper

Water Load Determination Approach in Two Wheeler Exhaust System

2018-10-30
2018-32-0075
Future emission norms in India (BS6) necessitates the 2 wheeler industry to work towards emission optimization measures. Engine operation at stoichiometric Air-Fuel Ratio (AFR) would result in a good performance, durability and least emissions. To keep the AFR close to stoichiometric condition, an Oxygen sensor is placed in the exhaust system, which detects if air-fuel mixture is rich (λ<1) or lean (λ>1) and provides feedback to fuel injection system for suitable fuel control. O2 sensor has a ceramic element, which needs to be heated to a working temperature for its functioning. The ceramic element would break (thermal shock) if water in liquid form comes in contact with it when the element is hot.
Technical Paper

Preparing BMW Motorrad’s Boxer Engine for the Future: Improving Performance, Driveability and Efficiency While Fulfilling Future Emission Standards

2018-10-30
2018-32-0083
Engine development mostly revolves around the same competing goals. With the implementation of the EU4 and EU5 emission standards for motorcycles, the difficulty of increasing performance and improving driveability and efficiency, while simultaneously fulfilling the Emission standards becomes even higher. Though the automotive industry offers a variety of solutions for the named topics, their implementation in a high performance motorcycle engine with specific needs regarding packaging, a wide operating range and full load behavior, represents a special challenge. This paper presents the approach of BMW Motorrad to meet these goals on the example of the boxer engine, focusing on the methodology throughout the development process. The gas exchange system of the engine was optimized using 1D gas dynamic simulations and 3D CFD analysis for a redesign of the valve train, ports and valves.
Technical Paper

Influences of Butanol Blends on Combustion and Emissions of a Small SI Engine

2018-10-30
2018-32-0058
In the general efforts to replace the fossil fuels in transportation by renewable fuels the bioalcohols are an important alternative. The global share of Bioethanol used for transportation is continuously increasing. Butanol, a four-carbon alcohol, is considered in the last years as an interesting alternative fuel, both for Diesel and for Gasoline application. Its advantages for engine operation are: good miscibility with gasoline and diesel fuels, higher calorific value than Ethanol, lower hygroscopicity, lower corrosivity and possibility of replacing aviation fuels. In the present work research with different nButanol portions in gasoline (BuXX)* was performed on the 2-cylinder SI engine with variations of several parameters on engine dynamometer. At different steady state operating points were varied: spark timing (αz), air excess factor (λ) and EGR-rate. Furthermore, the conversion rates and light-off of a 3-way-catalyst were investigated.
Technical Paper

Influence of Secondary Flow Generation on Heat Transfer inside the Fin Type Spiral Sub-Cooled Condenser by Experimental and CFD Analysis

2018-10-30
2018-32-0054
This paper discusses the compact structure, innovative and unique approach of high performance spiral coil sub-cooled condenser for compact power plant/engine applications. The motivation behind this study is to reduce the engine emission by improving the coefficient of performance for air-conditioning unit. Since the air conditioning system is the most power consumption units after the power plant, so it significantly affects the fuel consumption and the hazardous gas emissions. In the air condition cycle, the condenser unit is addressed as one of the important devices, and thus, the author tried to reduce the energy consumption by improving the performance of the condenser. The most advantage points of this study is to use spiral coil sub-cooled condenser, which elaborates the effect of secondary flow generation inside the fluid and is known as the Dean’s effect.
Technical Paper

Static Stress and Thermal Analysis of Connecting Rod using FE-Analysis

2018-10-30
2018-32-0034
In series of automobile engine, in running conditions, different components of engine undergoes static and dynamic loadings. While one of the main component known as connecting rod is used to convert linear motion of the piston to reciprocating motion of the crankshaft. In this paper, a comparison study on connecting rods made up of 42CrMo4 Alloy Steel (Forged steel) and 7075-T6 (SN) Aluminium Alloy is conducted to analyses the static and thermal stress, using the Finite Element Analysis (FEA). The main advantage of FEA is Virtual testing, it saves time and money. After measuring the dimension of connecting rod, the CAD model is developed in Solidworks software and imported to Solidworks Simulation software. Static stress analysis is done by fixing the crank end and the load is applied at the piston end of connecting rod and vice-versa. Maximum stress point and section prone to failure is found out by this analysis. Also, the thermal analysis of the connecting rod is performed.
Technical Paper

Model-Based Approach for Engine Performance Optimization

2018-10-30
2018-32-0082
State-of-the-art motorcycle engines consist of numerous variable components and require a powerful motor management to meet the growing customer expectations and the legislative requirements (e.g. exhaust and noise emissions, fuel consumption) at the same time. These demands are often competing and raise the level of complexity in calibration. In the racing domain, the optimization requirements are usually higher and test efficiency is crucial. Whilst the number of variables to control is growing, the time to perform an engine optimization remains the same or is even shortened. Therefore, simulation is becoming an essential part of the engine calibration optimization. Considering the special circumstances in racing, involving valuable hardware, as well as extremely short development and calibration iteration loops, only transient testing is possible.
Technical Paper

Lubricating Oil Droplets in Cylinder on Abnormal Combustion in Supercharged SI Engine

2018-10-30
2018-32-0008
The supercharged spark ignition engine has a problem of abnormal combustion at low speed and high load operating condition. This paper focuses on the sauce and mechanism of the abnormal combustion, namely, the behavior of lubricating oil droplets in cylinder, ring crevice, piston crown and ring gap. The experimental approach and the numerical analysis have been carried out. The two experimental approaches namely direct photography by high speed camera and measurement of scattering oil quantity at low speed condition have been tried. The photographs which is in engine operation show, 1st The oil droplets from ring crevice scatter every reciprocating motion and the diameter of oil droplets is between 0.10mm and 0.30mm. 2nd The oil droplets from piston crown has three steps as follows, firstly, the lubricating oil which reaches piston crown continues to accumulate, secondly, the accumulated lubricating oil scatters by the reciprocating motion.
Technical Paper

The Distributed Simulation of Intelligent Terrain Exploration

2018-10-30
2018-01-1915
In this study we consider the coordinated exploration of an unfamiliar Martian landscape by a swarm of small autonomous rovers, called Swarmies, simulated in a distributed setting. With a sustainable program of return missions to and from Mars in mind, the goal of said exploration is to efficiently prospect the terrain for water meant to be gathered and then utilized in the production of rocket fuel. The rovers are tasked with relaying relevant data to a home base that is responsible for maintaining a mining schedule for an arbitrarily large group of rovers extracting water-rich regolith. For this reason, it is crucial that the participants maintain a wireless connection with one another and with the base throughout the entire process. We describe the architecture of our simulation which is composed of HLA-compliant components that are visualized via the Distributed Observer Network tool developed by NASA.
Technical Paper

A Study of Friction Behavior of a Single Cylinder Gasoline Engine

2018-10-30
2018-32-0078
In order to improve the performance, fuel economy and future emission norms of a reciprocating engine, it is important to reduce the overall engine frictional losses. In this paper, author conducts an experimental study on the friction characteristics due to pumping loss, valve-train system, piston assembly, auxiliaries and transmission for a 110cc, single cylinder 4-stroke gasoline engine using frictional strip-down analysis. This paper deals with the friction performance results for the new concept piston skirt design called the unsymmetrical skirt for least piston skirt friction. Also, parameters like piston profile, oil film thickness optimized for least friction. The piston profile is arrived for optimum contact pattern with least piston slap noise. The modified engine reduced the engine friction by 10% in comparison to the base engine.
Technical Paper

Design, Development and Integration of a Wing-Morphing, Bimodal Unmanned Vehicle

2018-10-30
2018-01-1960
This paper relates to the design and development of a multi-modal UAV capable of aerial flight and underwater cruise. After traversing underwater, the multi-modal UAV could transit to the air by using the jet propulsion and help submarine carry the surveillance mission without exposing the submarine. A novel hybrid propulsion system has been manufactured and tested. Consisting of folding blades, the propeller has been optimised for propulsion both in air and water. The critical water to air transition phase is achieved by an additional impulsive thruster powered by a C02 cartridge. To decrease the drag in underwater cruise and reduce the potential damage when the vehicle impacts the water, a morphing wing has been developed. This consists of foam-carbon fibre lay-up constructed wings, which are driven by the linear servos, in a variable sweep configuration.
Technical Paper

Effect of Fuel Injection Timing on the Mixture Preparation in a Small Gasoline Direct-Injection Engine

2018-10-30
2018-32-0014
Gasoline direct-injection (GDI) engines have evolved as a solution to meet the current demands of the automotive industry. Benefits of a GDI engine include good fuel economy, good transient response, and low cold start emissions. However, they suffer from problems, like combustion instability, misfire, and impingement of fuel on in-cylinder surfaces. Therefore, to highlight the influence of fuel injection timing on in-cylinder flow, turbulence, mixture distribution and wall impingement, a computational study is conducted on a small-bore GDI engine. Results showed that air motion inside the engine cylinder is influenced by direct-injection of fuel, with considerable variation in turbulent kinetic energy at the time of injection. Due to charge cooling effect, mixture density and trapped mass were increased by about 10.8% and 9.5%, respectively.
Technical Paper

Multi-level Modeling Methodology for Aircraft Thermal Architecture Design

2018-10-30
2018-01-1910
This paper proposes a new methodology to conduct thermal analysis in the conceptual phase of the aircraft development process. Traditionally, thermal analysis is conducted after the system architecture has already been defined. The aircraft system thermal environment evaluation may lead to late design changes that can have a significant impact on the development process. To reduce the risk of late design changes, thermal requirements need to be defined and validated in the conceptual design phase. This research paper introduces a novel multi-level modeling strategy based on a bottom-up approach. It proposes an automatic geometrical simplification procedure for Computational Fluid Dynamic (CFD) analysis, a methodology for the generation of analytical correlations based on highly detailed methods, and a thermal risk assessment approach based on dimensionless numbers.
Technical Paper

Feedback on Application of MBSE Approach to an Avionics Subsystem

2018-10-30
2018-01-1922
This paper provides feedback on using a modelling approach to define an avionics subsystem in the frame of SAE ARP4754A aerospace recommended practices. Feedback concerns the practical use of models to support functional part of the following processes: “requirements capture”, “requirements validation”, and top-level part of “development of system architecture”. A Model-Based Systems Engineering approach has been proposed with a set of modelling tasks concerning views (diagrams, tables), patterns and transformations, and model checking rules. The goal of the approach is to structure functional needs and guide systems engineers in identification and definition of system functional interfaces and of system top level functions. This paper provides returns of experience on the application of that new approach on an industrial avionic case study known as the Onboard Maintenance System by a team mainly used to document centric approach until recently.
Technical Paper

The Fault-Augmented Approach for the Systematic Simulation of Fault Behavior in Multi-Domain Systems in Aerospace

2018-10-30
2018-01-1917
A library for modelling faults in multi-domain physical systems is introduced. The library is based on the simulation of fault effects on the system’s behavior. The motivation of how and why to model faults systematically as well as a description of the Modelica®-based library structure with a wizard supporting the semi-automatic augmentation process of faults are outlined. The fault types are classified into continuous and discrete with dedicated type definitions. The application of the Fault library is exemplified in the field of aerospace electrohydraulic actuator. The actuator is equipped with hydromechanical, electrical and digital systems for mitigating failures, which should be tested at an early stage of design. To perform the tests, a multi-domain, dynamic system model is created, wherein failures are systematically simulated using a special approach for fault augmentation.
Technical Paper

Power Dissipation Optimization for Solid State Power Control Modules in the Aircraft Secondary Power Distribution System

2018-10-30
2018-01-1930
In the last two decades, an aerospace industry trend in the secondary power distribution concept has been dominated by power electronics technology which includes power converters and Power Control Modules based on Solid State Power Control (SSPC) switching elements. These Power Control Modules, grouped around microprocessor based controllers and combined in a single electronic chassis, have become a backbone of electrical power distribution systems on all major commercial and military transport aircraft. Due to the resistive properties of the semiconductor-based SSPC devices, whose behaviors can be described as nonlinear functions of ambient operating temperature, power distribution system integration with SSPCs is challenged and heavily affected by operating temperatures and power dissipation limits. Although aircraft compartments where Power Control Modules are located are considered temperature and pressure controlled, high ambient operating temperatures are possible and expected.
Technical Paper

Power Quality Test Data Analysis for Aircraft Subsystem

2018-10-30
2018-01-1932
Aircraft subsystem development involves various combinations of testing and qualification activities to realize a flight worthy system. The subsystem needs to be verified for a massive number of customer requirements. Power Quality (PQ) testing is also an important testing activity carried out as a part of the environmental qualification test. It is intended to verify the functionality of subsystem with various power disturbances, to determine the ability of a subsystem to withstand power quality disturbances. The subsystem being designed should be reliable enough to handle power quality anomalies. Power quality test generates an enormous amount of test result data for analysis with millions of data samples depending on the test, and can be identified as Big Data. The engineer needs to analyze each set of test data as a part of post processing to ensure the power disturbances during testing are as per the standard requirements and functional performance of the subsystem is met.
Technical Paper

Development of the Multi-Resolution Modeling Environment through Aircraft Scenarios

2018-10-30
2018-01-1923
Multi-Resolution Modeling (MRM) is one of the key technologies for building complex and large-scale simulations using legacy simulators. MRM has been developed continuously, especially in military fields. MRM plays a crucial role to describe the battlefield and gathering the desired information efficiently by linking various levels of resolution. The simulation models interact across different local and/or distance area networks using the High Level Architecture (HLA) regardless of their operating systems and hardware. The HLA is a standard architecture developed by the US Department of Defense (DoD) and is meant to create interoperability among different types of simulators. Therefore, MRM implementations are very dependent on Interoperability and Composability. This paper summarizes the definition of MRM-related terminology and proposes a basic form of MRM system using Commercial Off-The-Shelf (COTS) simulators and HLA.
Technical Paper

Improving Manufacturing Efficiencies through Industry 4.0 Technologies in Aerospace

2018-10-30
2018-01-1929
1 In the age of 4th industrial revolution, operational and information technologies are increasingly getting converged to help organizations improve their topline through new innovative products and services, and improve bottom line by improving efficiencies. This transformation is driven by convergence of many advanced technologies such as advanced sensor and communication technologies, big data, advanced analytics, Artificial Intelligence (AI), robotics, additive manufacturing, virtual and augmented reality (VR/AR). Enterprises digitization journey continues to adopt advanced technologies through multi-pronged approach to achieve their near-term and long-term goals. This paper summarizes Industry 4.0 journey, its relevance and applications to aerospace.
Technical Paper

DC Arc Fault Detection Methods in MEA Distribution Systems

2018-10-30
2018-01-1934
Direct current (DC) for primary power distribution is a promising solution that is being explored by aircraft system integrators for MEA applications to enable the paralleling of non-synchronized engine off-take generators, and to enable the reduction of energy conversion stages required to supply electronically actuated loads. However, a significant challenge in the use of DC systems is the reliable detection of arc faults. Arcing presents a significant fire risk to aircraft and their presence can result in critical system damage and potentially fatal conditions. Series arc faults in DC systems are particularly challenging to detect as the associated reduction in system current eliminates the use of conventional overcurrent and current differential methods for fault detection. This paper provides an overview of series arc faults in DC systems and presents both simulation and hardware results to illustrate key trends, characteristics and discriminating features.
Technical Paper

A Structured Assurance Case for Commercial Off-The-Shelf (COTS) Airborne Electronic Hardware (AEH)

2018-10-30
2018-01-1939
One particular issue with Commercial Off-The-Shelf (COTS) components is that they are not developed to avionics industry standards and that their design and development data remain proprietary, hence are not available for review to the levels expected by those standards. The purpose of this research was to assess feasibility and to provide recommendations in how COTS components could be “assured” at system level, i.e. possibly going beyond ED-80/DO-254 for AEH or ED-79A/ARP-4754A standard for systems.
X