Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

How to Improve SI Engine Performances by means of Supercritical Water Injection

2019-09-15
2019-24-0235
The efficiency of ICEs is strongly affected by the heat losses of exhaust gases and engine cooling system, which account for about 60% of the heat released by combustion. Several technologies were developed to recover waste heat in ICEs, from turbochargers to ORCs, Stirling cycles and piezoelectric generation. A promising approach is to transfer the waste heat to a fluid, like water, and inject it into the combustion chamber. In such a way, the recovered energy is partially converted into mechanical work, by improving both engine efficiency and performance. In this work, the engine benefits obtained by using supercritical water as the vector to recover heat losses are analysed. Water has been chosen since it has a relatively high heat capacity and can be extracted directly from exhaust gases. A quasi-dimensional model has been implemented to simulate the ICE work cycle. Specifically, in this paper a spark ignition ICE, four-stroke with port fuel injection (PFI) has been considered.
Technical Paper

Knock Mitigation by Means of Coolant Control

2019-09-09
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

Efficient Test Bench Operation with Early Damage Detection Systems

2019-09-09
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.
Technical Paper

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

2019-09-09
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

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

2019-09-09
2019-24-0054
Due to its high benefit-cost ratio, decreasing mechanical friction losses in internal combustion engines represents one of the most effective and widely applicable solutions for improved engine efficiency. Especially the piston group – consisting of piston, rings and pin – shows significant potential for friction reduction, which can be evaluated through extensive experimental parameter studies. For each investigated variant, the steady-state friction measurements are fitted to an empirical polynomial model. In order to calculate the associated fuel consumption and CO2 emissions in transient driving cycles, the steady-state friction model is used in a map-based vehicle simulation. If transient engine operation entails friction phenomena that are not included in the steady-state model, the simulation could yield erroneous fuel consumption and CO2 predictions.
Technical Paper

Hybrid Powertrain Technology Assessment Through an Integrated Simulation Approach

2019-09-09
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).
Standard

Hydraulic Hose

2019-06-27
WIP
J517
This SAE Standard provides general, dimensional and performance specifications for the most common hoses used in hydraulic systems on mobile and stationary equipment. The general specifications contained in Sections 1 through 12 are applicable to all hydraulic hoses and supplement the detailed specifications for the 100R-series hoses contained in the later sections of this document (see Tables 1 and 2). This document shall be utilized as a procurement document only to the extent as agreed upon by the manufacturer and user. The maximum working pressure of a hose assembly comprising SAE J517 hose and hose connectors per SAE J516, SAE J518, SAE J1453, etc., shall not exceed the lower of the respective SAE maximum working pressure values. When using SAE J517 hose for marine applications, reference SAE J1475, SAE J1942, and SAE J1942-1. The SAE J517 100R9, 100R10, and 100R11 hoses are discontinued due to lack of demand. For DOD orders see Appendix C.
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.

Journal Article

Optimizing Cooling Fan Power Consumption for Improving Diesel Engine Fuel Efficiency Using CFD Technique

2019-06-11
Abstract Fan cooling system of an air-cooled diesel engine is optimized using 3D CFD numerical simulation approach. The main objective of this article is to increase engine fuel efficiency by reducing fan power consumption. It is achieved by optimizing airflow rates and flow distribution over the engine surfaces to keep the maximum temperature of engine oil and engine surfaces well within the lubrication and material limit, respectively, at the expense of lower fan power. Based on basic fan laws, a bigger fan consumes lesser power for the same airflow rate as compared to a smaller fan, provided both fans have similar efficiency. Flow analysis is also conducted with the engine head and block modeled as solid medium and fan cooling system as fluid domain. Reynolds-averaged Navier-Stokes turbulence (RANS) equations were solved to get the flow field inside the cooling system and on the engine liner fins. The Moving Reference Frame approach was used for simulating the rotation of a fan.
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

Glossary of Engine Cooling System Terms

2019-04-22
CURRENT
J1004_201904
The objective of this glossary is to establish uniform definitions of parts and terminology for engine cooling systems. Components included are all those through which engine coolant is circulated: water pump, engine oil cooler, transmission and other coolant-oil coolers, charge air coolers, core engine, thermostat, radiator, external coolant tanks, and lines connecting them.
Standard

Recommended Practices for Hydraulic Hose Assemblies

2019-04-16
WIP
J1273
SAE J1273 provides guidelines for selection, routing, fabrication, installation, replacement, maintenance, and storage of hose and hose assemblies for fluid-power systems. Many of these SAE Recommended Practices also may be suitable for other hoses and systems.
Technical Paper

Method Development and Application of Thermal Encapsulation to Reduce Fuel Consumption of Internal Combustion Powertrains

2019-04-02
2019-01-0902
Under bonnet thermal encapsulation is a method for retaining the heat generated by a running powertrain after it is turned off. By retaining the heat in the engine bay, the powertrain will be closer to its operating temperatures the next time it is started, reducing the warm up time required. This reduces the period of inefficiency due to high friction losses before the engine reaches it operating temperature, and as a result reduces the vehicles fuel consumption and CO2 emissions. To develop an integrated and efficient encapsulation design, CAE methods can be applied to allow this work stream to start as early in a vehicles development cycle as possible. In this work, the existing test methods are discussed, and a new Thermal CFD method is presented that accurately simulates the fluid temperatures after a customer representative 9 hour park period.
Technical Paper

Effects of Compression Ratio and Water Vapor Induction on the Achievable Load Limits of a Light Duty Diesel Engine Operated in HCCI Mode

2019-04-02
2019-01-0962
Among the various Low Temperature Combustion (LTC) strategies, Homogeneous Charge Compression Ignition (HCCI) is most promising to achieve near zero oxides of nitrogen (NOx) and particulate matter emissions owing to higher degree of homogeneity and elimination of diffusion phase combustion. However, one of its major limitations include a very narrow operating load range owing to misfire at low loads and knocking at high loads. Implementing HCCI in small light duty air cooled diesel engines pose challenges to eliminate misfire and knocking problems owing to lower power output and air cooled operation, respectively. In the present work, experimental investigations are done in HCCI mode in one such light duty production diesel engine most widely used in agricultural water pumping applications. An external mixture preparation based diesel HCCI is implemented in the test engine by utilizing a high-pressure port fuel injection system, a fuel vaporizer and an air preheater.
Technical Paper

Development of 4-Cylinder 2.0L Gasoline Engine Cooling System Using 3-D CAE

2019-04-02
2019-01-0156
To satisfy the global fuel economy restrictions getting stricter, various advanced cooling concepts, like active flow control strategy, cross-flow and fast warm-up, have been applied to the engine. Recently developed Hyundai’s next generation 4-cylinder 2.0L gasoline engine, also adopts several new cooling subsystems. This paper reviews how 3-D CAE analysis has been extensively used to evaluate cooling performance effectively from concept phase to pre-production phase. In the concept stage, the coolant flow in the water jacket of cylinder head and block was investigated to find out the best one among the proposed concepts and the further improvement of flow was also done by optimizing cylinder head gasket holes. Next, 3-D temperature simulation was conducted to satisfy the development criteria in the prototype stage before making initial test engines.
Technical Paper

Experimental Investigations to Extend the Load Range of Premixed Charge Compression Ignited Light Duty Diesel Engine through Fuel Modifications

2019-04-02
2019-01-0953
Premixed Charge Compression Ignition (PCCI) is one of the most promising low temperature combustion (LTC) strategies to achieve near zero oxides of nitrogen (NOx) and particulate matter (PM) emissions along with higher thermal efficiency. One of the major problems in diesel PCCI is a narrow operating load range because of very early ignition and knocking combustion at higher loads owing to higher reactivity of diesel fuel. Further, low volatile diesel resist vaporization, resulting in fuel spray wall wetting and higher unburned emissions in PCCI. Thus, high reactivity and low volatility of diesel fuel make it not suitable for PCCI combustion. The present work attempts to address these limitations, by blending diesel with high volatile and low reactive fuels, viz. gasoline and butanol at 10% and 20% blend levels by volume.
Technical Paper

Development of Advanced Non-Bypass Exhaust Heat Recovery System Using Highly Heat-Conductive SiC Honeycomb

2019-04-02
2019-01-0153
An exhaust heat recovery (EHR) system is an effective and attractive means of improving fuel economy and in-vehicle comfort, especially of hybrid cars in winter. However, many conventional bypass systems, which have a bypass pipe and bypass valve with a thermal actuator, are still large and heavy, and it is necessary not only to effectively improve the heat recovery but also to minimize the size and weight of EHR systems. Sakuma et al. reported new-concept heat exchangers and EHR systems using a highly heat-conductive SiC honeycomb, including a non-bypass system. However, since this non-bypass system always recovers heat from the exhaust gas, its heat recovery performance was set so as not to exceed the cooling capability of the radiator at a high engine load to prevent overheating of the vehicle.
X