Computational experience with a three-dimensional rotary engine combustion model

A new computer code was developed to analyze the chemically reactive flow and spray combustion processes occurring inside a stratified-charge rotary engine. Mathematical and numerical details of the new code were recently described by the present authors. The results are presented of limited, initial computational trials as a first step in a long-term assessment/validation process. The engine configuration studied was chosen to approximate existing rotary engine flow visualization and hot firing test rigs. Typical results include: (1) pressure and temperature histories, (2) torque generated by the nonuniform pressure distribution within the chamber, (3) energy release rates, and (4) various flow-related phenomena. These are discussed and compared with other predictions reported in the literature. The adequacy or need for improvement in the spray/combustion models and the need for incorporating an appropriate turbulence model are also discussed

Analysis of rotary engine combustion processes based on unsteady, three-dimensional computations

A new computer code was developed for predicting the turbulent, and chemically reacting flows with sprays occurring inside of a stratified charge rotary engine. The solution procedure is based on an Eulerian Lagrangian approach where the unsteady, 3-D Navier-Stokes equations for a perfect gas mixture with variable properties are solved in generalized, Eulerian coordinates on a moving grid by making use of an implicit finite volume, Steger-Warming flux vector splitting scheme, and the liquid phase equations are solved in Lagrangian coordinates. Both the details of the numerical algorithm and the finite difference predictions of the combustor flow field during the opening of exhaust and/or intake, and also during fuel vaporization and combustion, are presented

Conceptual design, evaluation and research identification for Remote Augmented Propulsive Lift Systems (RALS) with ejectors for VTOL aircraft

Ejector concepts for use with a remote augmented lift system (RALS) exhaust nozzle were studied. A number of concepts were considered and three were selected as having the greatest promise of providing the desired aircraft and exhaust gas cooling and lift enhancement. A scale model test program is recommended to explore the effects of the more important parameters on ejector performance

Effects of aircraft noise on flight and ground structures

Acoustic loads measured on jet-powered STOL configurations are presented for externally blown and upper surface blown flap models ranging in size from a small laboratory model up to a full-scale aircraft model. The implications of the measured loads for potential acoustic fatigue and cabin noise are discussed. Noise transmission characteristics of light aircraft structures are presented. The relative importance of noise transmission paths, such as fuselage sidewall and primary structure, is estimated. Acceleration responses of a historic building and a residential home are presented for flyover noise from subsonic and supersonic aircraft. Possible effects on occupant comfort are assessed. The results from these three examples show that aircraft noise can induce structural responses that are large enough to require consideration in the design or operation of the aircraft

TUMBUHAN KIRINYU Chromolaena odorata (L) (ASTERACEAE: ASTERALES) SEBAGAI INSEKTISIDA NABATI UNTUK MENGENDALIKAN ULAT GRAYAK Spodoptera litura

Kirinyu (Chromolaena odorata) adalah gulma berbentuk semakberkayu yang dapat berkembang cepat sehingga sulit dikendalikan.Tumbuhan ini merupakan gulma padang rumput yang sangatmerugikan karena dapat mengurangi daya tampung padangpenggembalaan. Selain sebagai pesaing agresif, kirinyu didugamemiliki efek allelopati serta menyebabkan keracunan bahkankematian pada ternak. Hasil penelitian menunjukkan gulma inidapat menjadi insektisida nabati karena mengandung pryrrolizidinealkaloids yang bersifat racun terhadap serangga. Makalah inimenguraikan potensi tumbuhan kirinyu sebagai insektisida nabatiuntuk mengendalikan ulat grayak. Ulat grayak adalah hama yangsulit dikendalikan karena perkembangbiakannya cepat sertamempunyai kisaran inang yang luas, yaitu hampir semua jenistanaman pangan dan hortikultura. Hama ini biasanya dikendalikandengan insektisida sintetis dengan dosis melebihi dari yangditentukan sehingga menyebabkan resistensi dan resurgensi. Olehkarena itu, perlu dicari pengganti insektisida sintetis agarpenggunaannya dapat dikurangi dengan menggunakan insektisidanabati. Ekstrak daun kirinyu efektif mengendalikan ulat grayakdengan mortalitas 80100% serta menekan tingkat kerusakan daunkedelai hingga 55,2%. Racun yang terkandung di dalam ekstrakkirinyu bersifat racun perut. Oleh karena itu, gulma ini perludikembangkan pemanfaatannya sebagai bahan insektisida nabatiagar bernilai ekonomis

Developing enterprise culture in a northern educational authority in the UK: involving trainee teachers in learning-orientated evaluation

In this paper we discuss our use of innovative methods - at least in the context of regeneration evaluation - to help evaluate an enterprise project in northern England, paying particular attention to the involvement of trainee teachers. We discuss the methods used and critically appraise the methods and methodology, present some emerging findings from the trainee teachers strand and conclude by discussing the place of what might be termed 'learning-orientated evaluation' in relation to the currently dominant output-focussed evaluation paradigm.</p