Fujio Nagao

Design and Trial Manufacture of A Free Piston Gas Generator

In order to investigate the fundamental phenomena in the free piston gas generator, we have reconstructed the Junkers type free piston air compressor into a gas generator of an inward compression type. The design data are as follows : [table] In the present paper, the design method, the constructional details and the performance of the test running are described.

Research on the Gas Leakage of Diesel Engine

The main function which the piston rings have to perform is to maintain tightness between the piston and the cylinder wall during the cycles. If the rings fail to fulfill this function in a satisfactory way, the consequence may be serious for the performance and starting of the engine. The influence of the gas leakage on the engine performance has been theoretically and experimentally investigated by making the cy1inder gas leak through a small orifice set on the cylindercover. The results obtained are summarized, using the leakage factor K (leakage area/displacement per second). 1. Power loss due to the gas leakage increases nearly in proportion to the gas leakage which depends only on K. 2. Specific power loss is larger at the lowere load, because the leakage is independent of the load. 3. The engine starts at a certain value of K, which varies with the inlet temperature.

The Thermal Efficiency of Free Piston Gas Turbines

The free piston gas turbine will be classified into several cycles by the method of heating the compressed air, the fundamental cycles of wich are Pescara, constant pressure combustion, regeneration and regenerative constant pressure combustion cycle. By analysing the reversible air cycles of them thermodynamically, the relations among thermal efficiency and principal factors were obtained. The thermal efficiency of the three cycles except Pescara can be determined by the three factors, namely, thermal efficiency of engine cylinder, pressure ratio in compressor cylinder and ratio of turbine inlet temperature to the atmospheric one. While the efficiency of Pescara cycle can be determined only by arbitrary two factors among them and is equal to that of a Sabathe cycle which has the same max. pressure, degree of explosion and cut-off ratio as the engine cylinder of Pescara and operates on the atmospheric pressure. Assuming that the efficiency of engine cylinder is equal to 60% and the ratio of turbine inlet temperature to the atmospheric one 3, the max. thermal efficiency and the pressure ratio for each cycle were calculated as follows : [table]

Fluttering of the Piston Rings in a High Speed Internal Combustion Engine

本文は高速内燃機関において, ある高い回轉速度で現われるピストンリングの持ち上がりによるガス漏洩の著増現象に関し, 一様な矩形斷面を有するものを用いるときの, リングの幅および厚みの影響ならびにリングの数の効果について述べたものである.

Research on Gasoline-Injection Spark-Ignition Engine (3 rd Report) : Comparison of Performances of Engine Using a Carburetor and Cylinder Injection

本文は前報までの実驗結果を基礎として單シリンダディーゼル機関を改造し, これをガソリン噴射電氣点火式機関となし, 噴射弁および点火せんに対する最良條件を見出し, 機関性能を調べ, さらに氣化器を使用して同じ運轉條件の下に性能試驗を施行し兩形式の得失を比較したものである.

Research on the Fuel Injection of the High Speed Diesel Engine

本研究はBosch燃料ポンプ及び噴射弁を用ひ種々の運轉状態のもとに於てポンプの送出弁の出口及び噴射弁の入口における圧力、同時に弁運動を電気容量により測定し噴射の遅れ、噴射時間、噴射圧力、及び弁運動の相互関係並にこれ等に及ぼす各種の影響を見出した。回轉數は毎分900を中心に最低100から1, 500の間で實驗を行つた。

New Torsion Dynamometers

從來動力計と稱せられるものは凡てモーメントのみを測定するものでこれにより動力を測定するには同時に回轉數をも測定せねばならぬ。著者は從來の動力計とは全く趣を異にしたモーメントと回轉數の積即ち動力を直接に測り得る傳達動力計を數種考案しその中2種類を試作し試驗した。その原理は何れも電動機の起電力が回轉數に比例する性質及び傳達モーメントと共に一次的に變化する他の機構とを用ひ回轉數とモーメントの積を測定するにある。試驗の結果その取扱ひも比較的容易で且正確である。尚本測定法によれば計器1個にして直ちに動力を讀み得るのみならず從來至難とされてゐた急激に變化する動力及び積算動力をも測定することが出來る。