A Matching Problem between the Front Fan and Aft Fan Stages in Adaptive Cycle Engines with Convertible Fan Systems

In the process of studying the steady-state performance and component matching of adaptive cycle engines with convertible fan system, it was found that the front fan and aft fan stage have a unique matching problem when the mode select valve is closed and engine is operating at higher Mach number conditions. The cause of this matching problem was studied with numeric simulation in this paper. Based on the features of adaptive cycle engines with convertible fan system, the possible methods and their feasibilities of solving this matching problem were also discussed. According to the results, the flow rate adjustment capacity of the aft fan stage directly determines the occurrence and severity of this matching problem. The matching problem can be ameliorated in some extent by either reducing the design second bypass ratio or adjusting the variable geometry mechanisms, but it cannot be completely solved at the aspect of component matching mechanism.

The Study of Sedimentary Characteristics of the Fan Delta of Yingcheng Formation in Lishu Fault Depression

On the base of drilling cores, summarizing some sedimentary facies marks, such as grain size characteristics, sedimentary structures, log curve, etc, it is analyzed the sedimentary characters of fan delta of Yingcheng formation in Lishu fault depression according to drilling well sedimentary analysis. The study area grows two subfacies, fan-delta plain and front fan-delta, existing 6 microfacies which are debris flow, distributary channels, interdistributary bay, submerged distributary channe, mouth bar and submerged distributary interchanne. Then the depositional model of gentle slope type fan delta is established.On the plane, fan delta existing in this area has characters of contiguous development and mixed-source deposition; In the longitudinal direction, deposition lithologic section developed in the period of water withdrawal is built on the retrograding lithologic section developed in the period of water inlet.

Wuerxun Depression Fan Delta Depositional System Research of Nantun Formation in Wubei Sub-Depression

Fan delta facies deposition are developed in the steep slope of faulted lake basin and have features ,such as the rapid accumulation, from near provenance, clastic coarse granularity and poor sorting. By means of core, logging, well logging and seismic data, based on the sedimentary characteristics of Nantun formation of Wuerxun depression, the conclusions are as followings: Faulted basin steep slope belts are developed fan delta depositional system with volcano facies in Wubei sub-depression of Wuerxun depression;The fan delta system are divided into plain,front and front fan delta etc,three subfacies, seven microfacies; In distributary channel microfacies, sand conglomerate, gravel sandstone, middle-grit are main lithology, low maturity, poor sorting to medium, vertical sequence, visible bottom gravel and erosion surface, large scale cross-bedding are developed, partial visible horizontal bedding; channel mouth bar microfacies relatively rudimentary, lithology with sorting relatively good powdermiddle sandstone, development of small cross-bedding, horizontal bedding.

A Novel Airflow Management System With Redundant Fan Field Replaceable Units

A novel airflow architecture for a networking chassis will be described in this work. This chassis is a pull system with two sets of four fans located in series at its exhaust. Each set of four fans is a field replaceable unit (FRU). The unique feature of this chassis is that one set of fans, called the rear fan FRU, is replaceable from the rear side of the chassis and the other set of fans, called the front fan FRU, is replaceable from the front side of the chassis. Computational fluid dynamics simulations and measurement data show this chassis is capable of providing up to 78% – 79% of its maximum cooling capacity when one fan FRU is removed from the chassis, and up to 62% – 67% of its maximum cooling capacity when one fan FRU has failed.

Research of the XF3-1 Turbofan Engine

A research program of low bypass ratio small front fan engines has been in process at Third Research Center of Technical Research and Development Institute of Japan Defence Agency since 1975. The final target of this program is the development of the propulsion engine for the high subsonic small aircraft. As the first phase of this program, the bench test engine XF3-1 was manufactured and the basic studies of the overall engine matching performance and the effect of each component on the engine performance have been carried out. This paper describes the XF3-1 engine, reviews the status of the research and presents the major engineering progress attained through the research.

Recent Status on Development of the Turbofan Engine in Japan

Efforts to design and develop new jet engines have been made in Japan since 1953. One family of propulsion engine (J3) succeeded in getting into production to be installed on two models of Japanese developed aircraft (T1B and P2J). Another family of lift engine (JR) has been successfully used for overall VTOL system studies. Based upon these experiences, studies on a new fan engine for main propulsion are being carried out. This new engine (FJR-710) is a high bypass front fan engine developed for low noise generation and low smoke emission.

High Bypass Ratio Compound Fan-Shaft Engines for Convertible Rotary Wing Aircraft

This paper presents design arrangements and performances of high bypass ratio compound fan-shaft engines. Helicopter rotor drive power can be obtained from the propulsion fan engine by unloading the fan. This is accomplished by using variable fan guide vanes that can be closed to reduce fan air flow or by reducing fan speed. These methods of unloading the fan are substantiated by the results of tests. The basic designs considered are for engines in the 5 to 30 lb/sec gas producer airflow size class and which have a two-spool coaxial front fan with a bypass ratio of approximately 8.0 and pressure ratio of approximately 1.4. The front fan configuration is used to superchange the gas producer. The flow of energy that results during power sharing between propulsive fan thrust and helicopter rotor drive power is discussed; in addition, fan shaft engine performance data are presented as applied to representative stowed-rotor convertiplanes of 15,000 and 60,000-lb design gross weights.