Refine Your Search

Search Results

Author:
Viewing 1 to 4 of 4
Technical Paper

Experimental and Modelling Study of Variable Cycle Time for a Reversing Flow Catalytic Converter for Natural Gas/Diesel Dual Fuel Engines

2000-03-06
2000-01-0213
This paper presents an investigation of a reverse flow catalytic converter attached to a diesel/natural gas dual fuel engine. Experimental data were obtained in a ceramic monolith catalytic converter with a palladium based catalyst. A variety of flow reversal cycle times were explored experimentally when the engine load was changed from a high load to a low load. A single channel numerical model was developed for the data set and the effect of reverse flow cycle time was studied using both physical and numerical model systems. The duration of the cycle time is shown to be an important parameter in the operation of the converter. Shorter cycle times produced the least fluctuation in reactor temperature and gave the highest time-averaged conversion. Intermediate cycle times gave the most rapid increase in the maximum reactor temperature.
Technical Paper

Underwater Heat Engines Using Non-Conventional Atmospheres

1997-05-01
971674
Long range, extended endurance, variable speed autonomous underwater vehicles (AUVs) appear to be an attractive solution to problems of environmental monitoring, geophysical exploration and military surveillance. To undertake their intended autonomous missions these vehicles require reliable and cost-effective power systems. Although there is presently an extensive interest in untethered AUVs, with far reaching efforts being made in a variety of activities, only limited headway has been made in the development of power systems which could be readily integrated into these vessels. The majority of current research is focusing on increasing the underwater endurance and hence cost effectiveness of the vehicle by developing compact, lightweight high energy density power systems for vessel propulsion. Subsequently, a number of different power systems have been investigated proposed, designed and developed.
Technical Paper

Development of an IDI Diesel Engine Test Facility for Use with Non-Conventional Atmospheres

1992-08-03
929059
It has been known for nearly a century that by recycling the exhaust gas and adding renewal oxygen for combustion, it is possible to operate a standard diesel engine in air restricted conditions. However in order to operate under these conditions, such as found in underwater vessels, exhaust gas management systems are required to process the combustion products. The characteristics of recycled working fluids and the effective disposal of the exhaust gases leads to conflicting system operational requirements. In order to operate the whole system as a compact and efficient power unit, a compromise needs to be found between the performance of the engine with the recycled exhaust and the physical size and efficiency of the exhaust processing system. Previous research using non-conventional or contaminated atmospheres for underwater vehicles power systems, pollution control and mine engineering has mainly used three methods of supplying the intake atmosphere.
Technical Paper

A Thermodynamic Model of an Air-Independent IDI Diesel Engine System

1992-08-03
929058
Synthetic atmosphere diesel (SAD) engines have been and are still being developed as air-independent power systems for use in naval and commercial underwater vehicles. Although the basic concept of such a system is relatively simple, its practical implementation is somewhat complicated and normally involves expensive and time consuming prototype development. If an analytical method existed which could be used to compare the overall performance of different configurations or highlight essential control aspects, system optimization could be attempted more readily and a close-to-optimum design produced prior to any subsequent practical development. Consequently, a thermodynamic simulation model has been formulated so that the performance and/or design of such systems can be investigated, and the effects of the various system variables can be identified. In this paper the development of the model and the associated experimental investigation is described.
X