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2003-06-23
Technical Paper
2003-01-2265
Hideo Kawamura, Mitsuru Akama
In order to improve the fuel consumption and control exhaust emissions in a heat insulation engine, fuels reformed CH4 by CO2 and steam were used. Porous metal plate coated Li2ZrO3 was used to make CO2 separate from the exhaust gas of the engine. CH4 and CO2 gas are supplied to the catalytic converter and reformed CO and H2gas increased to 30% on kinetic energy are supplied to the engine as well as gas and steam turbine is installed to recover the exhaust gas energy. As the result the thermal efficiency of the engine systems will be improved to about 57.5% compared with 42% of conventional diesel engine.
2002-10-21
Technical Paper
2002-01-2692
R. A. Beg, M. S. Rahman, P. K. Bose, B. B. Ghosh
Vegetable oils are characterised as diesel engine fuel due to their properties of adiabatic combustion under high pressure and temperature. The semi-adiabatic type of engines can be effectively utilized for achieving the best performance from combustion of vegetable oils. The present study reports the performance and exhaust emissions of such type of engine by using diesel fuel - linseed oil blends and esterified linseed oil and the results as obtained are compared with that of 100% diesel fuel operation. The influence of coating thickness and compression ratio have also been reported. Results show that BSFC, exhaust gas temperature, CO level and smoke density are increased but Br. Th. Effic. and NOx level are decreased both in diesel fuel - linseed oil blends and esterified linseed oil compared to 100% diesel fuel operation. Results with esterified linseed oil are comparatively better than diesel fuel - linseed oil blends with higher degree of insulation.
1998-10-19
Technical Paper
982541
Ales Hribernik
A statistical method is described which allows a very accurate determination of the correlation between pressure and volume. The basis of the method is the pressure measurement of an engine under motoring conditions and correcting the pressure diagram with respect to heat and blow-by losses. Computation of the polytropic exponent dependent on error of phase lag determines the correlation in the pressure volume diagram. Since the internal processes in an IC engine under motoring conditions differ significantly from the ones under firing conditions, some modifications in the heat and blow-by losses models are necessary in order to be successfully applied in the proposed method. A simple optimization approach has therefore been used to correct both models. Several pressure diagrams measured under engine motoring conditions and at the different engine speeds have been studied.
1996-02-01
Technical Paper
960089
Howard W. Christenson
The ideal internal-combustion crankshaft engine would burn all the fuel near top center without detonation, then expand the whole charge until exhaust Both events are impossible with current piston engines. The Hydrocycle Rocket Piston Engine concept employs a free piston in the head of a two-stroke-cycle engine. Combustion between the crank piston and the free piston allows direct conversion of combustion fluid expansion to hydrostatic fluid flow and accumulator gas compression with perfect timing and minimum thermal and mechanical losses. An infinitely variable, radial hydrostatic motor gives the driver smooth, gas-cushioned acceleration and stepless performance. Maximum economy is attained since the driver is forced to run the engine at optimum minimum speed to match road load oadin all traffic conditions.
1995-02-01
Technical Paper
950979
Lloyd Kamo, Ardy Kleyman, Walter Bryzik, Ernest Schwarz
Lubrication of advanced high temperature engines has been one of the greatest obstacles in the development of the Adiabatic engine. Liquid lubricants which gave lubricating properties as well as heat removal function can no longer carry out this duty when piston ring top ring reversal temperatures approach 540°C. Solid lubricants offer some hope. Since solid lubricants cannot perform the heat removal function, its coefficient of friction must be very low, at least <0.10, in order to prevent heat build up and subsequent destruction to the piston rings and cylinder liners. The Hybrid Piston concept developed in the U.S. Army Advanced Tribology program offers some hope, since the top solid lubricant ring slides over the bottom hydrodynamic lubricant film section during each stroke. This paper presents the progress made with the solid lubricant top ring in the Hybrid Piston. Four materials have shown promise in the laboratory to fullfil its mission.
1994-03-01
Technical Paper
940946
Allan J. Ferrenberg
This paper describes a new form of reciprocating engine and the work accomplished to date to investigate the capabilities and feasibility of this engine. This engine offers the substantial performance advantages that are thermodynamically possible when regeneration is applied to a low heat rejection (LHR) engine. Under a contract with the Naval Surface Warfare Center, a computer model that is capable of modeling the complex processes occurring in the LHR regenerated engine has been constructed. This model is being used to assess and examine the performance of various engine designs. In addition, design and materials issues associated with the most critical new component, the regenerator, are being investigated. Throughout this program, Caterpillar, Inc. has provided valuable technical support.
1994-03-01
Technical Paper
940951
Melvin E. Woods, Walter Bryzik, Ernest Schwarz
An advanced low heat rejection engine concept has successfully completed a 100 hour endurance test. The combustion chamber components were insulated with thermal barrier coatings. The engine components included a titanium piston, titanium headface plate, titanium cylinder liner insert, M2 steel valve guides and monolithic zirconia valve seat inserts. The tribological system was composed of a ceramic chrome oxide coated cylinder liner, chrome carbide coated piston rings and an advanced polyolester class lubricant. The top piston compression ring Included a novel design feature to provide self-cleaning of ring groove lubricant deposits to prevent ring face scuffing. The prototype test engine demonstrated 52 percent reduction in radiator heat rejection with reduced intake air aftercooling and strategic forced oil cooling.
1993-03-01
Technical Paper
930988
Ernest Schwarz, Michael Reid, Walter Bryzik, Eugene Danielson
The purpose of this paper is to investigate combustion and performance characteristics for an advanced class of diesel engines which support future Army ground propulsion requirements of improved thermal efficiency, reduced system size and weight, and enhanced mobility. Advanced ground vehicle engine research represents a critical building block for future Army vehicles. Unique technology driven engines are essential to the development of compact, high-power density ground propulsion systems. Through an in-house analysis of technical opportunities in the vehicle ground propulsion area, a number of dramatic payoffs have been identified as being achievable. These payoffs require significant advances in various areas such as: optimized combustion, heat release phasing, and fluid flow/fuel spray interaction. These areas have been analyzed in a fundamental manner relative to conventional and low heat rejection “adiabatic” engines.
1993-03-01
Technical Paper
930989
Xiaobo Sun, Wenguang G. Wang, Donald W. Lyons, Xiaohong Gao
A set of experiments were conducted to evaluate the performance differences between a Low Heat Rejection Engine (LHRE) which is ceramic-insulated and a conventional baseline metal diesel engine which is water-cooled. Both engines were single cylinder, direct injection, and turbocharged. The objective of the study was to investigate the rate of heat release of these engines so that performance improvement procedures could be obtained. In this paper, the difference of the ignition delay between the two engines was determined. Two methods for improving the combustion process of the LHRE were studied: use of mixture fuels and increase the fuel injection rate. Both methods proved effective and reduced the fuel consumption rate of the LHRE.
1993-03-01
Technical Paper
930986
Dennis N. Assanis, Evangelos, James A. E. Bell
This paper describes the concept and a practical implementation of piston-compounding. First, a detailed computer simulation of the piston-compounded engine is used to shed light into the thermodynamic events associated with the operation of this engine, and to predict the performance and fuel economy of the entire system. Starting from a baseline design, the simulation is used to investigate changes in system performance as critical parameters are varied. The latter include auxiliary cylinder and interconnecting manifold volumes for a given main cylinder volume, auxiliary cylinder valve timings in relation to main cylinder timings, and degree of heat loss to the coolant. Optimum designs for either highest power density or highest thermal efficiency (54%) are thus recommended. It is concluded that a piston-compounded adiabatic engine concept is a promising future powerplant.
1993-03-01
Technical Paper
930985
Eugene Danielson, David Turner, Joseph Elwart, Walter Bryzik
High thermal stresses in the cylinder heads of low heat rejection (LHR) engines can lead to low cycle fatigue failure in the head. In order to decrease these stresses to a more acceptable level, novel designs are introduced. One design utilizes scallops in the bridge area, and three others utilize a high-strength, low thermal conductivity titanium faceplate inserted into the firedeck (combustion face) of a low heat rejection engine cylinder head. The faceplates are 5mm thick disks that span the firedeck from the injector bore to approximately 10mm outside of the cylinder liner. Large-scale finite element models for these four different LHR cylinder head configurations were created, and used to evaluate their strength performance on a pass/fail basis. The complex geometry of this cylinder head required very detailed three-dimensional analysis techniques, especially in the valve bridge area. This area is finely meshed to allow for accurate determination of stress gradients.
1993-03-01
Technical Paper
930984
Zhang Nanlin, Zhong Shengyuan, Feng Jingtu, Cai Jinwen, Pu Qinan, Fan Yuan
A commercially available water-cooled engine Model 6105 was modified into an adiabatic engine without independent cooling water system. The modified engine was built to have monolithic ceramic composite pistons and zerconia coatings on the firedeck of cylinder heads, the disk surface of inlet and exhaust valves, and the upper part of cylinder liners. Its supercharging system and fuel injection system were adjusted. The test results showed that such modifiation could lead to an improvement up to 5.5% of fuel consumption over the baseline engine. Having undergone a 400-hour endurance stand test, the engine was installed in a bus, and has been completed a on-board trial covering more than 10000km.
1993-03-01
Technical Paper
931021
Walter Bryzik, Ernest Schwarz, Roy Kamo, Melvin Woods
A high output experimental single cylinder diesel engine that was fully coated and insulated with a ceramic slurry coated combustion chamber was tested at full load and full speed. The cylinder liner and cylinder head mere constructed of 410 Series stainless steel and the top half of the articulated piston and the cylinder head top deck plate were made of titanium. The cylinder liner, head plate and the piston crown were coated with ceramic slurry coating. An adiabaticity of 35 percent was predicted for the insulated engine. The top ring reversal area on the cylinder liner was oil cooled. In spite of the high boost pressure ratio of 4:1, the pressure charged air was not aftercooled. No deterioration in engine volumetric efficiency was noted. At full load (260 psi BMEP) and 2600 rpm, the coolant heat rejection rate of 12 btu/hp.min. was achieved. The original engine build had coolant heat rejection of 18.3 btu/hp-min and exhaust energy heat rejection of 42.3 btu/hp-min at full load.
1992-02-01
Technical Paper
920541
Melvin Woods, Walter Bryzik, Ernest Schwarz
1991-11-01
Technical Paper
912502
E. Khoshravan
Numerical calculation based on finite element method are carried out to calculate the temperature field in an adiabatic diesel engine piston having diameter. 127 mm and made of aluminum alloy. The engine cylinder wall have the coated externally by a thin layer of very high grade ceramic insulating material. The isothermic distribution in the piston body and the heat flow rates to the cooling media at different loads have been depicted for both cases with and without insulation coating. The paper first reviews the current state of development of ‘adiabatic’ diesel engine in Europe, U.S.A and the Japan. This review section is followed by a brief description of the common element of hostile features, then comes the experimental program on thermally insulated components for single cylinder engine in the research center of Tabriz and finally by a theoretical section dealing with the performance potential of composed engine schemes based on ‘adiabatic’ engine operation.
1991-02-01
Technical Paper
910461
Katsuyuki Osawa, Roy Kamo, Edgars Valdmanis
The cylinder of the aluminum engine block without iron sleeve was coated directly with thin thermal barrier coatings of zirconia and chrome oxide. The cylinder head and valve face and the piston crown were also coated. These three engine components were tested individually and together. The fuel consumption performance of this 84 x 70 mm direct injection diesel engine improved 10% with only coated cylinder bore. When the fuel injection timing of the coated cylinder bore engine was retarded by about 2°CA, emissions characteristics were approximately the same level as for the baseline engine with 8% improvement in brake specific fuel consumption compared with the baseline engine. At constant fuel flow rate to the engine, the exhaust and cylinder head temperatures were higher for the insulated bore case. One can summarize the combustion temperature must have been higher and heat release rates were faster in the insulated case.
1991-02-01
Technical Paper
910459
Mark J. Jennings, Thomas Morel
Recently, several theories have been offered as possible explanations for claimed increases in diesel engine heat transfer when combustion chamber surface temperatures are raised through insulation. A multi-dimensional computational fluid dynamics (CFD) analysis, using a recently developed near wall turbulent heat transfer model, has been employed to investigate the validity of two of these theories. The proposed mechanisms for increased heat transfer in the presence of high wall temperatures are: 1 piston-induced compression heating of the near wall gas which increases the near wall temperature gradient when wall temperatures are high; 2 increased penetration of hot, burned gases into the near wall flow during combustion through reduction of the flame quench distance.
1991-02-01
Technical Paper
910457
Melvin E. Woods, Ernest Schwarz, Walter Bryzik
An advanced low heat rejection engine concept has been selected based on a trade-off between thermal insulating performance and available technology. The engine concept heat rejection performance is limited by available ring-liner tribology and requires cylinder liner cooling to control the piston top ring reversal temperature. This engine concept is composed of a titanium piston, headface plate and cylinder liner insert with thermal barrier coatings. Monolithic zirconia valve seat inserts, and thermal barrier coated valves and intake-exhaust ports complete the insulation package. The tribological system is composed of chrome oxide coated cylinder, M2 steel top piston ring, M2 steel valve guides, and an advanced polyol ester class lubricant.
1991-02-01
Technical Paper
910455
Peter A. Gaydos
Abstract In support of development efforts for advanced heat engines, self-lubricating materials were evaluated for their friction and wear characteristics above 260 C. The work focused on the ring/cylinder interface and tested self-lubricating ring or cylinder specimens against plasma-sprayed chromia or other ceramic materials. Three materials were chosen for the evaluation. Two of them were solid lubricant compacts, and one was a self-lubricating coating. The compacts were the Westinghouse (Boes) compact and a commercially available molybdenum disulfide-based composite. The coating consisted of a wear-resistant matrix filled with solid lubricating materials to reduce friction. The Boes compact resulted in high temperature friction and wear results that were in some cases equal to or better than those of earlier tests run with liquid lubrication. The other compact and the coating both had much higher wear and coefficients of friction than the Boes compact.
1991-02-01
Technical Paper
910895
James A.E. Bell
A new practical concept for piston compounding engines is described. The calculated thermal efficiency of a fully insulated, piston compounded, overcharged diesel engine can exceed 60%. The design considerations for construction of such an engine from controlled expansion superalloys is also described.
1991-02-01
Technical Paper
910297
Gerhard Woschni, Karl Huber
A modified equation for the heat transfer coefficient has been established, because the original equation proposed by the author in 1967 provides at low load and motored operation to low results. The reason for this descrepancy seems to be a steady state soot layer, the thickness of which increases with increasing load, where as it does not exist in a motored engine. All equations for the heat transfer coefficient known either to, do not represent the real heat transfer coefficient accuring at the soot layer surface, but include the thermal conductivity resistance of the soot layer. The real heat transfer coefficient is more than two times higher than assumed up to now. These results also show the adiabatic engine in a totally new light.
1990-04-01
Technical Paper
900911
Allan J. Ferrenberg
The engine described in this paper has the following features and potential improvements over conventional gasoline or Diesel engines: 1. Much higher thermal efficiency, 2. Lower emissions, 3. Less stringent fuel requirements, 4. No ignition system required for steady operation, 5. Highly efficient operation at low compression ratios, 6. High power to displacement ratio, 7. Similar to conventional engine hardware. In this paper the thermodynamic advantages of regeneration with Otto and Diesel cycle engines are presented, along with a brief description of past attempts to provide regeneration in a reciprocating internal combustion engine. Finally, the single cylinder regenerated internal combustion engine concept is presented and described, along with its inherent and potential features, advantages, challenges, and issues.
1990-02-01
Technical Paper
900621
Patrick Badgley, Roy Kamo, Walter Bryzik, Ernest Schwarz
A previous paper (1)* described the performance improvements which can be obtained by using an “adiabatic” (uncooled) engine for military trucks. The fuel economy improved 16% to 37% (depending upon the duty cycle) and was documented by dynamometer testing and vehicle testing and affirmed by vehicle simulation. The purpose of this paper is to document a NATO cycle 400 hour durability test which was performed on the same model adiabatic engine. The test results showed that the engine has excellent durability, low lubricating oil consumption and minimal deposits.
1990-02-01
Technical Paper
900622
Xu Zhi Wei, Gu Hong Zhong
Much effort has been made to develop ceramic engine. Power turbines are usually used to recover excessive exhaust energy. The unsatisfactory problems are their high initial cost, complex structure and poor acceleration response. In the new system suggested here, the excessive exhaust energy is transferred to crank work through the pre-expanding process by higher pressurized intaked air during the intake stroke, thus the cycle temperature is lowered. Both thermodynamic analysis and performance simulation of this system were made, results showed that the fuel consumption of the new system could achieve the lever of power turbine's. A test bed of turbocharged engine was used to study the performance of the new system. Because of its simple structure, high acceleration response and low cycle temperature which leads to low NOx emission, this system is thought to be a competitive candidate for adiabatic engine sets.
1990-02-01
Technical Paper
900624
Hideo Kawamura
An adiabatic engine was constructed with the monolithic type ceramic material. A highly durable and superior heat insulating engine could be completed, through detailed study of the design, evaluating the ceramics of which reliability is inferior in strength, going back to the microstructure and improving it to the utilizable level as the engine parts. I started studying the combustion in a bid to accomplish improvement of the fuel consumption rate, realization of multi-fuel engine and pollution-lowering, but I found out that recovering of the ignition delay shortening can be coped with by high pressure injection, fuel nature modification and so forth. In future, I have to pursue my studies in connection with reduction of emission of exhaust gas like the NOx and recovery of energy from the exhaust gas, and the similar subjects.
1990-02-01
Technical Paper
900623
Melvin Woods, Paul Glance, Ernest Schwarz
Abstract A highly effective thermal insulating piston concept with high projected durability characteristics has been developed by means of computer aided modelling, thermal rig bench screening, and small-bore engine testing. The piston concept is composed of a relatively low thermal conductivity titanium alloy type 6242 structural material and a 1.25 mm thick slurry densified thermal barrier coating. The piston material, structural configuration, and detail design features were selected through computer aided modelling and qualified through small-bore engine testing. Screening of plasma sprayed thermal barrier coatings was performed on a simple thermal test rig and final selection of a system was made through small-bore engine testing.
1990-02-01
Technical Paper
900404
Falk K. Börsch, Manfred W. Langer
This article is a report on the properties of certain interesting ceramic materials and on their use in engine components. A critical study is made of the results of applications to adiabatic diesel engines. An outline is given of some experimental results relating to the frictional and wear characteristics of ceramic materials. Details are also given of the effect which a ceramic turbocharger rotor has on the speed of response of the turbocharger unit.
1989-02-01
Technical Paper
890571
Dennis N. Assanis, Edward Badillo
Finite element models of various fast-response thermocouple designs have been developed. Due to the small differences in thermal properties between thermoelements and metal engine components, standard co-axial thermocouples can measure transient temperatures of metal components within an accuracy of 98%. However, these relatively small errors in total temperature measurement translate into as high as 30% errors in indicated peak-to-peak-temperature swings for iron surfaces. The transient swing errors result in up to 30% errors in peak heat flux rates to iron surfaces. These peak heat flux errors can be substantially larger if coaxial thermocouples are used for heat flux measurements in aluminum or ceramic surfaces. Increasing the thin film thickness is a compromise solution to reduce the discrepancy in peak heat flux measured with coaxial designs in metal engines. An alternative overlapping thin film thermocouple design has also been evaluated.
1989-02-01
Technical Paper
890570
Wai K. Cheng, Victor W. Wong, Fuquan Gao
The performance and heat transfer characteristics of a single cylinder diesel engine in the metal and in the ceramic-coat-insulated configurations were compared at the same speeds, loads and air flow rates. Compared to the metal engine, the insulated engine had a higher brake specific fuel consumption which was attributed to a slower combustion process; the exhaust as well as the time averaged surface temperatures of the insulated engine were higher. The unsteady heat flux amplitudes in the insulated engine were lower which suggested a lower overall heat flux. This lower heat flux was attributed to the lower flame temperatures because of the poor combustion quality in the non-optimized insulated engine.
1989-02-01
Technical Paper
890572
Thomas Morel, Syed Wahiduzzaman, Edward F. Fort, Dale R. Tree, David P. DeWitt, Kenneth G. Kreider
Detailed heat transfer measurements were made in the combustion chamber of a Cummins single cylinder NH-engine in two configurations: cooled metal and ceramic-coated. The first configuration served as the baseline for a study of the effects of insulation and wall temperature on heat transfer. The second configuration had several in-cylinder components coated with 1.25 mm (0.050″) layer of zirconia plasma spray -- in particular, piston top, head firedeck and valves. The engine was operated over a matrix of operating points at four engine speeds and several load levels at each speed. The heat flux was measured by thin film thermocouple probes. The data showed that increasing the wall temperature by insulation reduced the heat flux. This reduction was seen both in the peak heat flux value as well as in the time-averaged heat flux. These trends were seen at all of the engine operating conditions.
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