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.
SUMMARY OF FLUIDIC THRUST VECTORING RESEARCH CONDUCTED AT NASA LANGLEY RESEARCH CENTER
Interest in low-observable aircraft and in lowering an aircraft's exhaust system weight sparked decades of research for fixed geometry exhaust nozzles. The desire for such integrated exhaust nozzles was the catalyst for new fluidic control techniques; including throat area control, expansion control, and thrust-vector angle control. This paper summarizes a variety of fluidic thrust vectoring concepts that have been tested both experimentally and computationally at NASA Langley Research Center. The nozzle concepts are divided into three categories according to the method used for fluidic thrust vectoring: the shock vector control method, the throat shifting method, and the counterflow method. This paper explains the thrust vectoring mechanism for each fluidic method, provides examples of configurations tested for each method, and discusses the advantages and disadvantages of each method.
Reading research critically: assessing the validity and reliability of research instrumentation--Part 2.
Accurate measurement of research variables is necessary so that research consumers can trust that it is the research intervention that affected the change in the outcome variable, not some extraneous error component. Reliability is the accuracy with which the research instruments measure the variable that they are designed to measure. A number of known threats to instrument reliability should be anticipated by the researcher and looked for the consumer. These threats are presented in this article.