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Technical Paper

CFD Modeling of Compact Heat Exchangers for I.C. Engine Oil Cooling

2019-08-15
2019-24-0179
In the last years, the increase of the specific power of the modern engines has required a parallel improvement of the performances of the cooling system. In this context, also the control of the oil temperature has become an important issue, leading to the introduction of dedicated cooling circuits (air-cooled or liquid-cooled). Among the two, the liquid-cooled solution results in a more compact installation in which the oil-to-liquid heat exchanger is directly mounted on the engine block and integrated in the engine cooling system. It is clear that, in a liquid-cooled solution, the design of the heat exchanger represents an issue of extreme concern, which requires a compromise between different objectives: high compactness, low pressure drop, high heat-transfer efficiency. In this work, a computational framework for the CFD simulation of compact oil-to-liquid heat exchangers, including offset-strip fins as heat transfer enhancer (turbolator), has been developed.
Technical Paper

Replacing twin electric fan radiator with Single fan radiator Abstract.

2019-08-15
2019-24-0181
Downsizing is one of the crucial activities being performed by every automotive engineering organisation. The main aim is to reduce – Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchange is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction.
Technical Paper

Direct performance comparison between conventional and integrated exhaust manifold (IEM) design

2019-08-15
2019-24-0180
Integrated Exhaust Manifold (IEM) technology has recently become of interest in production engine design as a technical response to increasing specific power output and stricter limits on engine emission. Indeed, the added cooling effect of exhaust runners integrated in the cylinder head allows for a significant reduction in fuel enrichment and consequent CO and HC emissions. Furthermore, IEM can result in overall weight and cost savings due to the exclusion of a conventional exhaust manifold. The IEM implementation offers considerable challenges to the design of the engine cylinder head, which is an already highly loaded and function-dense component. The integration of the exhaust runners in the cylinder head leads to a radical increase of the surface exposed to high thermal loads. In order to prevent thermal failure, the runners need to be enveloped in a coolant jacket.
Technical Paper

Knock Mitigation by means of Coolant Control

2019-08-15
2019-24-0183
The potentiality of knock mitigation by means of the control of the coolant flow rate is investigated. As a first step, the dynamic behavior of the wall temperature in response to a sudden variation of the coolant flow rate is analyzed experimentally in a small displacement, 4-valve per cylinder SI engine, which is equipped with an electrically driven pump. Subsequently, the influence of the wall temperature on knock onset is analyzed through a zero-dimensional model and the Livengood and Wu integral. Finally, an experimental activity on the engine test bed is carried-out in order to evaluate the influence of the coolant flow rate and of the engine inlet coolant temperature on the knock phenomenon. Results show that, even though a retarded spark advance and a mixture enrichment are not avoidable in the early stage of knock onset, a cooling control can help reducing the time of use of these fuel consuming strategies in the case of prolonged high-load conditions.
Technical Paper

Hybrid powertrain technology assessment through an integrated simulation approach

2019-08-15
2019-24-0198
Global automotive fuel economy and emissions pressures mean that 48V hybridisation will become a significant presence in the passenger car market. The complexity of the powertrain solutions is increasing in order to further increase fuel economy for hybrid vehicles and maintain robust emissions performance. However, this results in complex interactions between technologies which are difficult to identify through traditional development approaches, resulting in sub-optimal solutions for either vehicle attributes or cost. This paper presents the results from a simulation programme focussed on the optimisation of various advanced powertrain technologies on 48V hybrid vehicle platforms. The technologies assessed include an electrically heated catalyst, an insulated turbocharger, an electric water pump and a thermal management module (a coolant valve replacing a conventional thermostat).
Technical Paper

Validation of Using a Steady-State Friction Model for Determining CO2 Emissions in Transient Driving Cycles

2019-08-15
2019-24-0054
MAHLE is conducting extensive parameter studies regarding friction savings on the piston group of fired gasoline and diesel engines to further increase the efficiency of the internal combustion engine. For each tested piston variant, steady-state fired friction measurements are taken across the entire operating range of the engine using the indication method. Based on these measurements, an empirical model is created which describes the Friction Mean Effective Pressure (FMEP) depending on engine speed, engine load and coolant and oil temperature. The friction map is then used in a drive cycle simulation in order to determine fuel consumption and CO2 emissions. A drive cycle corresponds to transient conditions both as a result of the changes in operating point and the engine warm-up. The current legislative drive cycles aim to better reflect real-world driving conditions and thus contain frequent and steep transient events.
Technical Paper

Efficient Test Bench Operation with Early Damage Detection Systems

2019-08-15
2019-24-0192
The efficient operation of test benches within the framework of research and development projects directly correlates with the "health" of the examinee to be investigated. The use of so-called Early Damage Detection Systems (EDDS) is becoming increasingly popular for reasons of Unit Under Test (UUT) monitoring. In the context of this publication the expectations of an EDDS and its structure are discussed as well as its advantages and disadvantages in test bench operation analyzed and compared with the results of measurements. The used EDDS should primarily prevent the damage, up to the loss of the test object by a total loss, in order to ensure a finding possibility of the damaged part at the examined test object. A deviation of the test object behavior from the undamaged condition must be recognized in an early status and must lead to a shutdown of the test bench operation after reaching a defined limit value.
Standard

Formed Tube Ends for Hose Connections and Hose Fittings

2019-06-20
WIP
J1231

This SAE Standard provides general and dimensional specifications for formed tube ends and hose fittings. These connections are intended for general applications in low pressure automotive and hydraulic systems on automotive, industrial, and commercial products. The fittings shown in Figures 2 and 3 are intended to be retained by hose clamps as specified in SAE J1508.

It is recommended that where step sizes or additional types of fittings are required, they be designed to conform with the specifications of this document insofar as they may apply. The following general specifications shall supplement the dimensional data contained in the tables with respect to all unspecified detail.

Technical Paper

Simulation of Ice Particle Breakup and Ingestion into the Honeywell Uncertified Research Engine (HURE)

2019-06-10
2019-01-1965
Numerical solutions have been generated which simulate flow inside an aircraft engine flying at altitude through an ice crystal cloud. The geometry used for this study is the Honeywell Uncertified Research Engine (HURE) which was recently tested in the NASA Propulsion Systems Laboratory (PSL) in January 2018. The simulations were carried out at predicted operating points with a potential risk of ice accretion. The extent of the simulation is from upstream of the engine inlet to downstream past the strut in the core and bypass. The flow solution is produced using GlennHT, a NASA in-house code. A mixing plane approximation is used upstream and downstream of the fan. The use of the mixing plane allows for steady state solutions in the relative frame. The flow solution is then passed on to LEWICE3D for particle trajectory, impact and breakup prediction. The LEWICE3D code also uses a mixing plane approximation at the boundaries upstream and downstream of the fan.
Technical Paper

An Experimental Study to Evaluate Hydro-/Ice-Phobic Coatings for Icing Mitigation over Rotating Aero-engine Fan Blades

2019-06-10
2019-01-1980
Ice accretion on aero-engines, especially on the fan blades, is the very hazardous icing incident due to the potential performance degradation of jet-engines. In the present study, an experimental investigation was conducted to examine the performance of ice-phobic coatings for jet-engine fan icing mitigation. The experimental study was performed in the unique Icing Research Tunnel at Iowa State University (ISU-IRT) with a scaled engine fan model operated under wet glaze and dry rime ice conditions. To evaluate the effects of anti-icing coatings and to acquire the important details of ice accretion and shedding process on fan blade surfaces, a “phase-locked” imaging technique was applied with a high-resolution imaging system. The power input required to drive the engine fan model rotating at a constant prescribed speed was also measured during the ice accretion experiment.
Technical Paper

An Ice Shedding Model for Rotating Components

2019-06-10
2019-01-2003
A CFD simulation methodology is presented to evaluate the ice that sheds from rotating components. The shedding detection is handled by coupling the ice accretion and stress analysis solvers to periodically check for the propagation of crack fronts and possible detachment. A novel approach for crack propagation is highlighted where no change in mesh topology is required. The entire computation from flow to impingement, ice accretion and crack analysis only requires a single mesh. The accretion and stress module are validated individually with published data. The analysis is extended to demonstrate potential shedding scenarios on three complex industrially-relevant 3D cases: a helicopter blade, an engine fan blade and a turboprop propeller. The largest shed fragment will be analyzed in the context of FOD damage to neighboring aircraft/component surfaces.
Technical Paper

A Study on NVH Performance Improvement of TPE Air Intake Hose Based on Optimization of Design and Material

2019-06-05
2019-01-1491
Environmental and fuel economy regulations (Eu 6d and WLTP RDE) on automobiles have been tightened recently. To counter this regulation, the global automobile industry is focusing on weight reduction, fuel efficient turbo charger, cooled EGR, thermal management, low friction and so on. However, the high-speed turbocharger makes turbulence, and resulting in airflow noise. This noise is transmitted indoor through the air intake system, which adversely affects the vehicle's competitiveness. Therefore, for turbo engine, it is essential to reduce the noise of the air intake system. The air intake system consists of air cleaner, air filter, air intake hose and air duct. The air flow noise of turbo-engine is mainly the emission noise emitted from the walls of air intake system. And the transfer path of turbo noise is in order of air intake hose, air cleaner and air duct. Therefore, it is effective to reduce the noise of the air intake hose located at the beginning of noise transfer path.
Standard

Moisture Transmission Test Procedure--Hydraulic Brake Hose Assemblies

2019-05-14
WIP
J1873
This SAE Recommended Practice is intended for all vehicle hydraulic brake hoses. It is an accelerated test which is intended to provide the user with a method of comparing the ability of hydraulic brake hose designs to retard the ingress of moisture into brake fluid. This document specifies a laboratory performance requirement. ASTM D 1364 interlaboratory reproducibility and correlation of data have not been defined, nor has correlation been established between field vehicle brake fluid moisture content and data obtained by this document.
Standard

Using a System Reliability Model to Optimize Maintenance Costs A Best Practices Guide

2019-05-07
CURRENT
JA6097_201905
SAE JA6097 (“Using a System Reliability Model to Optimize Maintenance”) shows how to determine which maintenance to perform on a system when that system requires corrective maintenance to achieve the lowest long-term operating cost. While this document may focus on applications to Jet Engines and Aircraft, this methodology could be applied to nearly any type of system. However, it would be most effective for systems that are tightly integrated, where a failure in any part of the system causes the entire system to go off-line, and the process of accessing a failed component can require additional maintenance on other unrelated components.
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