International Journal of Turbo & Jet-engines 

About: International Journal of Turbo & Jet-engines is an academic journal published by De Gruyter. The journal publishes majorly in the area(s): Turbine & Gas compressor. It has an ISSN identifier of 0334-0082. Over the lifetime, 1144 publications have been published receiving 5987 citations. The journal is also known as: International journal of turbo and jet engines (Print).

Semi-Inverse Method of Establishing Generalized Variational Principles for Fluid Mechanics With Emphasis on Turbomachinery Aerodynamics

Abstract: The semi-inverse method suggested by the author is one of the best and most convenient ways to deduce generalized variational principles with multi-variables from 1) partial differential equations (PDE) and boundary conditions (BC), or 2) known variational principles with single variable or double variables, or 3) a suitable energy trial-functional, without any crisis variational phenomenon. As a result two families of generalized variational principles for irrotational compressible blade-to-blade flow have been deduced without using the Lagrange multiplier method. The method will have a great effect not only in fluid mechanics, but also in elasticity theorems.

A Review of Friction Damping of Turbine Blade Vibration

Abstract: This paper reviews recent research on analyzing and designing friction dampers to reduce turbine blade vibration. It discusses previous literature reviews, methods of analysis, models of friction constraint , methods of modelling the structural aspects of the system, procedures for optimizing the damper 's design, and some research on related problems. The author a t t empts to indicate some of the limitations and advantages of the cited methods. Conclusions are drawn concerning the current state-ofthe-art and recommendat ions are made regarding directions for fu ture research and development.

Studies on aerated-liquid atomization

Abstract: The atomizing performance of an aerated-liquid atomizer operating under conditions of bubbly flow is investigated. The device tested consists of a plain-orifice atomizer with provision for injecting air or gas through a porous tube into a flowing liquid stream. Measurements of mean drop size and drop-size distribution are made using a light diffraction technique. Water injection pressures are varied from 173 to 690 kPa (25 to 100 psid) and gas/liquid ratios from 0.001 to 0.05 by mass. The results obtained show that good atomization can be achieved using only small amounts of atomizing gas at injection pressures as low as 173 kPa (25 psid). Moreover, atomization quality appears to be largely independent of the size of the nozzle discharge orifice. However, the bubbly flow mechanism of atomization is limited to low gas/liquid mass ratios, the actual value depending on the injection pressure. High injection pressures permit high values of air/liquid ratio.

Active Control of Suddenly Expanded Flows from Overexpanded Nozzles

Abstract: An experimental investigation was carried out to study the effectiveness of micro-jets to control base pressure in suddenly expanded axi-symmetric ducts. Four micro-jets of 1 mm orifice diameter located at 90$^\circ$ interval along a pitch circle diameter of 1.3 times the nozzle exit diameter in the base region was employed as active controls. The Mach numbers of the suddenly expanded flows were studies 2.0, 2.5 and 3.0. The jets were expanded suddenly into an axi-symmetric tube with cross-sectional area 2.56, 3.24, 4.84, and 6.25 times that of nozzle exit diameter. The length-to-diameter ratio of the sudden expansion tube was varied from 10 to 1. The jets were operated at an over expansion level of Pe/Pa = 0.277. The wall pressure distribution in the suddenly enlarged duct was also measured. It is found that the micro-jets can serve as active controllers for base pressure. Also, the wall pressure distribution is not adversely influenced by the micro-jets. From the present investigation it is evident that for a given Mach number and nozzle pressure ratio one can identify the enlargement length to diameter ratio which will result in maximum increase/decrease of base pressure.

Fuel Performance Evaluation for the Solid-Fueled Ramjet

Abstract: : The potential energetic performance of fuel ingredients for the use in the solid fuel ramjet is presented in terms of the enthalpy of combustion per unit mass and per unit volume of the fuel. Combustion phenomena and combustion efficiency are briefly discussed, but are not accounted for in evaluating the theoretical fuel performance. Practical considerations rule out the use of beryllium, which is extremely toxic, and metal hydrides (especially boranes) which are both toxic and great fire hazards. Compared with hydrocarbons, some metal compounds have somewhat higher energy per unit mass, but up to about three times higher energy per unit volume. Boron has the highest energy density (energy per unit volume) of all elements, while among all other fuel candidates only boron compounds exhibit similar potential performance. Other possible high performance fuel candidates are boron carbide, which is the least expensive source of boron, A1B(12) (alloy) with energy density slightly exceeding that of elemental boron, and the high borides of magnesium and silicon.