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Investigation Into Improved Low-Temperature Urea-Water Solution Decomposition by Addition of Titanium-Based Isocyanic Acid Hydrolysis Catalysts and Surfactant

Southwest Research Institute-Ryan Hartley, Nolan Wright, Cary Henry
University of Texas-Zachary Tonzetich
  • Technical Paper
  • 2020-01-1316
To be published on 2020-04-14 by SAE International in United States
Mitigation of urea deposit formation and improved ammonia production at low exhaust temperatures continues to be one of the most significant challenges for current generation SCR aftertreatment systems. Various technologies have been devised to alleviate these issues including: use of alternative reductant sources and thermal treatment of the urea-water solution (UWS) pre-injection. The objective of this work is to expand the knowledge base of a potential third option, which entails chemical modification of UWS by addition of titanium-based urea/isocyanic acid (HNCO) decomposition catalysts and/or surfactants to the fluid. Physical mixtures of urea and varying concentrations of ammonium titanyl oxalate (ATO), oxalic acid, and titanium dioxide (TiO2) were generated, and the differences in NH3 and CO2 production were evaluated. It was found that addition of 2.0 mol % ATO to urea increased CO2 production by 821 % and NH3 production by 96 % at temperatures ≤ 215 °C, indicating significantly enhanced hydrolysis of HNCO. Conversely, is was demonstrated that addition of oxalic acid or TiO2 to urea exhibited little effect on NH3 and CO2 production, indicating…
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Validation of a Theoretical Model for the Correction of Heat Transfer Effects in Turbocharger Testing through a Quasi-3D Model

Politecnico di Milano-Gianluca Montenegro, Matteo Tamborski, Augusto Della Torre
Universita Degli Studi di Genova-Silvia Marelli
  • Technical Paper
  • 2020-01-1010
To be published on 2020-04-14 by SAE International in United States
In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The accuracy of turbocharger performance map constitute the basis for the tuning and validation of a numerical 1D procedure, usually adopted for the engine-turbocharger matching. Actually, it is common practice in automotive applications to use simulation codes, which require as an input the value of efficiency. Therefore, the ability to correct the measured performance maps taking into account internal heat transfer would allow the implementation of commercial simulation codes used for engine-turbocharger matching calculations. The practical purpose of an adiabatic test program is to obtain an accurate measurement of the work transfer, and of the real efficiency of compressor and turbine (unaffected by internal and external heat transfer rates). In fact, the heat flow leads to an apparent increase of the power absorption and an apparent drop in efficiency of the compressor. However, lack of understanding of the heat transfer effects as well as the high costs associated…
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High Efficiency Intake System Leveraging Exhaust Thermal Boost

Finitronx-Xianzhe Jia
University of Pennsylvania-Qianyu Ouyang
  • Technical Paper
  • 2020-01-0277
To be published on 2020-04-14 by SAE International in United States
This IC engine amelioration tackles the hurdling barrier of ICE’s intrinsic efficacy limit through innovative mechanical design of a consolidated system encompassing intake bypass and coordinating injection mechanism. To be specific, a CFD-optimized passage is constructed alongside the intake and injection design which utilizes multi-stage variable mixing precisely, taking full advantage of exhaust temperature elevation. Regenerative heat gained through exhaust system gives rise to flexible amount of thermal dynamics adjustment to the intake. Furthermore, variable geometry intake port is developed based on maximizing air-fuel interaction rate under different circumstances, where high temperature turbulence optimization is implemented in ANSYS Fluent. Pin-slider mechanic design at intake interface enables modular variable intake routing supporting engine efficiency promotion. Regarding ECU development, integrated valve, intake airflow, as well as injection control are designed to cooperate with each other under the supervisory control module. First, optimal controlled valve system is devised at the junction of bypass, which achieves improved response accuracy and combustion sufficiency with flow and temperature regulation. Secondly, a closed-loop injection control strategy fulfills variable in-cylinder combustion tuning with…
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Spatially Optimized Diffusion Alloys: A Novel Multi-Layered Steel Material for Exhaust Applications

Arcanum Alloys Inc.-Zachary Detweiler, David Keifer, Daniel Bullard
Tenneco Inc.-Adam Kotrba, Tony Quan, Winston Wei
  • Technical Paper
  • 2020-01-1051
To be published on 2020-04-14 by SAE International in United States
A novel Spatially Optimized Diffusion Alloy (SODA) material has been developed and applied to exhaust systems, a very aggressive environment with high temperatures and loads, as well as excessive corrosion. Traditional stainless steels disperse chromium homogeneously throughout the material, with varying amounts ranging from 11% to 18% dependent upon its grade (e.g. 409, 436, 439, and 441). SODA steels, however, offer layered concentrations of chromium, enabling an increased amount along the outer surface for much needed corrosion resistance and aesthetics. This outer layer, approximately 70µm thick, exceeds 20% of chromium concentration locally, but is only 3% in bulk, offering selective placement of the chromium to minimize its overall usage. And, since this layer is metallurgically bonded, it cannot delaminate or separate from its core, enabling durable protection throughout manufacturing processes and full useful life. The core material may be of various grades, however, so this study employs interstitial free steel (low carbon), which offers not only commercial advantages, but also eases manufacturing operations, as it is more formable than stainless steel grades. The material and…
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A Vehicle Level Transient Thermal Analysis of Automotive Fuel Tanks

FCA US LLC-Alaa El-Sharkawy, Dipan Arora
Optumatics LLC-Yehia Mazen, Amr Sami
  • Technical Paper
  • 2020-01-1342
To be published on 2020-04-14 by SAE International in United States
Maintaining the fuel temperature and fuel system components below certain values is an important design objective. Predicting these temperature is therefore one of the key parts of the vehicles thermal management process. One of the physical processes affecting fuel tank temperature is fuel vaporization, which is controlled by the vapor pressure in the tank, fuel composition and fuel temperature. Models are developed to enable the computation of the fuel temperature, fuel vaporization rate in the tank, fuel temperatures along the fuel supply lines, and follows its path to the charcoal canister and into the engine intake. For Diesel fuel systems where a fuel return line is used to return excess fluid back to the fuel tank, an energy balance will be considered to calculate the heat added from the high-pressure pump and vehicle under-hood and underbody. In this work, a transient heat transfer model is developed to compute the heat transfer between the in-tank fuel and the vehicle under-hood or underbody where the effect of exhaust and convection are considered. A fuel vaporization model is…
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Design and Optimization of a Muffler integrated with an Adaptive Quarter Wave Tube for Noise Reduction in Commercial Vehicles

VE Commercial Vehicles, Ltd.-Arun Cherkkil, Ajay Rathor
  • Technical Paper
  • 2020-01-0507
To be published on 2020-04-14 by SAE International in United States
With rising concerns on internal combustion engine noise levels in commercial vehicles, it is necessary to attenuate noises present in specific frequency bands. This can be achieved with the implementation of a quarter wave tube on the present exhaust system. Historically such passive attenuators have been efficient only at specific engine speeds and exhaust gas temperatures. A new exhaust flow actuated adaptive quarter wave tube design is proposed here which can give significant noise attenuation at various engine operating conditions. The proposed design eliminates the requirement of complex electronic actuating mechanisms for the adaptive quarter wave tubes and replaces the same by perforated diaphragms and spring loaded trap door mechanisms, which are more robust and effective. The module can be integrated with the turbo S-flow muffler which is installed on most of the commercial vehicles. A design is conceptualized and developed using CAD tools. The performances for various combinations of quarter wave tube and muffler lengths are compared using Finite Element Analysis. A comparative study on the transmission losses achieved by the current muffler design…
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Experimental and 1D Numerical investigations on the exhaust emissions of a small Spark Ignition engine considering the cylinder-by-cylinder variability

Istituto Motori CNR-Luca Marchitto, Luigi Teodosio, Cinzia Tornatore, Gerardo Valentino
University of Naples-Fabio Bozza
  • Technical Paper
  • 2020-01-0578
To be published on 2020-04-14 by SAE International in United States
The stringent legislations on pollutant and CO2 emissions require relevant efforts to improve both the combustion efficiency and the exhaust emissions of internal combustion engines. In the case of spark ignition (SI) engines, various techniques have been tested and implemented in the last generation SI engine architectures. On the other hand, a reduced emphasis has been posed on the analysis of individual cylinder behavior, since a systematic sub-optimal operation may occur, due to cylinder-by-cylinder non-uniformities. The main purpose of this work is to accurately forecast the combustion and the exhaust emissions of a twin-cylinder turbocharged SI engine, taking into account the overall performance and individual cylinder-by-cylinder operation, with particular attention to volumetric efficiency, injected fuel quantity, and residuals content. To this aim, a dedicated experimental activity is performed on the engine under investigation. Preliminary measurements have shown relevant differences in combustion evolution in the two cylinders, mainly ascribed to variations in the injected fuel quantities, which in turn depend on the fuel rail geometry . As a consequence, cylinder out emissions are also quite different…
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Integration of Sensitivity Analysis and Design for Six Sigma (DFSS) Methodology into Transient Thermal Analysis

FCA US LLC-Alaa El-Sharkawy, Dipan Arora
Optumatics LLC-Amr Sami, Abd El-Rahman Hekal
  • Technical Paper
  • 2020-01-1389
To be published on 2020-04-14 by SAE International in United States
In this paper we present an integrated approach which combines analysis of the effect of simultaneous variations in model input parameters on the component or system temperatures. The sensitivity analysis can be conducted by varying model input parameters using specific values that may be of interest to the user. The alternative approach is to use a structured set of parameters generated in the form of DFSS DOE matrix. The matrix represents a combination of simulation conditions which combine the control factors (CF) and noise factors. CF’s are the design parameters that the engineer can modify to achieve a robust design. Noise factors include parameters that are outside the control of the design engineer. In automotive thermal management, noise factors include changes in ambient temperature, exhaust gas temperatures or aging of exhaust system or heat shields for example. The integrated approach, presented in this paper, provides powerful tools that can significantly reduce the total simulation time and helps to provide robust thermal protection scenarios. The relative importance of the CF’s can be estimated and the least…
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Microstructure-Fatigue Property Relationships for Cast Irons

National Research Council (Canada)-Xijia Wu
  • Technical Paper
  • 2020-01-0187
To be published on 2020-04-14 by SAE International in United States
Cast irons are widely used for combustion engine/exhaust system applications, not only because they are less expensive but also because they offer some attractive properties such as good thermal conductivity, relatively high specific yield strength, and good oxidation resistance. Cast irons can be made with a wide variety of microstructures containing either flake-like graphite (FG), nodular graphite (NG) or vermicular graphite (VG), or mixing of the above, which control their mechanical and fatigue properties. In this paper, a microstructure-fatigue property relationship model is developed, combining the Tanaka-Mura-Wu’s fatigue crack nucleation model with Eshelby’s solution for materials containing ellipsoidal inclusions. This applies to cast irons considering its microstructural graphite characters (shape, size, elastic modulus and Poisson’s ratio). This model is used to analyse ductile cast iron (DCI) with nodular graphite (NG) microstructure, grey cast iron (GCI) with flake-like graphite (FG) microstructure, and compacted graphite iron (CGI) with vermicular graphite (VG) microstructure. Excellent agreement is found between the model prediction and the experimental data or the Coffin-Manson-Basquin correlations at room temperature. Further development will be to incorporate…
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Development of Exmani-Heat protector to Improve Sound Absorption using New Perforated Thin Aluminum Plate

Hyundai Motor Group-Jaegi Sim, Minsoo Kim, KwangMin Yoon
  • Technical Paper
  • 2020-01-0405
To be published on 2020-04-14 by SAE International in United States
This technology is a technology for reducing the gas flow noise generated from the noise of the vehicle, especially the exhaust system. The primary function of the heat protector is thermal shutdown. However, due to the increase in engine power, downsizing of engines, and the rise of consumer's eye level, solutions about noise are now emphasized. Established the manufacturing technology of 3-ply composite board which can absorb sound in the existing heat protector. For this purpose, mold technology for punching aluminum sheet, optimization technique for punching effect, unique high-strength / high-forming pattern design, sound absorbing material selection and composite sheet molding technology, and noise vibration reduction mounting technology for plate joining were developed.