Computational investigation on infrared radiation characteristic for two-dimensional vectoring nozzles with fluidic injection
Relative to the thrust vectoring nozzle by mechanical means, fluidic injection vectoring nozzle outshines on the strength of uncomplicated structure, light weight and low cost. Research on infrared characteristic of fluidic injection vectoring nozzles is highly vital for nozzle technology development and military application. Numerical simulation for infrared characteristic of the two-dimensional fluidic injection vectoring nozzles was conducted employing self-developed program software. Based on the computational results, it can be concluded that two-dimensional throat skewing nozzle possesses optimal infrared characteristic suppression effect among the nozzle schemes.
Advancements in exhaust system technology for the 21st century
With a desire to reduce high performance fighter exhaust systems weight and cost, advanced exhaust system technology is focused on producing fixed geometry, lighter weight nozzles while maintaining high system performance. Fluidic injection for multiaxis vectoring, throttling and mixing is being investigated to provide mission critical performance in these simple fixed geometry systems. Recent developments in fluidic injection systems are reviewed and projections are given for further development and application of this technology to 21* Century air vehicles.
Heritage Languages: In the 'Wild' and in the Classroom
Heritage speakers are people raised in a home where one language is spoken who subsequently switch to another dominant language. The version of the home language that they have not completely acquired – heritage language – has only recently been given the attention it deserves from linguists and language instructors. Despite the appearance of great variation among heritage speakers, they fall along a continuum based upon the speakers’ distance from the baseline language. Such a continuum-based model enables researchers and instructors to classify heritage speakers more accurately and readily. This article discusses the results of research on lower-proficiency speakers, identifying recurrent features of heritage languages in phonology, morphology, and syntax. Preliminary results indicate that different heritage languages share a number of structural similarities; this finding is important for the understanding of general processes involved in language acquisition. The article also presents implications of the main findings for language education and identifies areas needing further study.