Three-dimensional marginal separation

The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different

Delta launch vehicle inertial guidance system (DIGS)

The Delta inertial guidance system, part of the Delta launch vehicle improvement effort, has been flown on three launches and was found to perform as expected for a variety of mission profiles and vehicle configurations

Unsteady three-dimensional marginal separation, including breakdown

A situation involving a three-dimensional marginal separation is considered, where a (steady) boundary layer flow is on the verge of separating at a point (located along a line of symmetry/centerline). At this point, a triple-deck is included, thereby permitting a small amount of interaction to occur. Unsteadiness is included within this interaction region through some external means. It is shown that the problem reduces to the solution of a nonlinear, unsteady, partial-integro system, which is solved numerically by means of time-marching together with a pseudo-spectral method spatially. A number of solutions to this system are presented which strongly suggest a breakdown of this system may occur, at a finite spatial position, at a finite time. The structure and details of this breakdown are then described

Long period nodal motion of sun synchronous orbits

An approximative model is formulated for assessing these perturbations that significantly affect long term modal motion of sun synchronous orbits. Computer simulations with several independent computer programs consider zonal and tesseral gravitational harmonics, third body gravitational disturbances induced by the sun and the moon, and atmospheric drag. A pendulum model consisting of evenzonal harmonics through order 4 and solar gravity dominated nodal motion approximation. This pendulum motion results from solar gravity inducing an inclination oscillation which couples into the nodal precession induced by the earth's oblateness. The pendulum model correlated well with simulations observed flight data

The response of a laminar boundary layer in supersonic flow to small amplitude progressive waves

The effect of a small amplitude progressive wave on the laminar boundary layer on a semi-infinite flat plate, due to a uniform supersonic freestream flow, is considered. The perturbation to the flow divides into two streamwise zones. In the first, relatively close to the leading edge of the plate, on a transverse scale comparable to the boundary layer thickness, the perturbation flow is described by a form of the unsteady linearized compressible boundary layer equations. In the freestream, this component of flow is governed by the wave equation, the solution of which provides the outer velocity conditions for the boundary layer. This system is solved numerically, and also the asymptotic structure in the far downstream limit is studied. This reveals a breakdown and a subsequent second streamwise zone, where the flow disturbance is predominantly inviscid. The two zones are shown to match in a proper asymptotic sense

Development of Japanese elementary curriculum that emphasises spoken-ness

This paper discusses the curriculum development which aims to enhance the spoken-ness or naturalness of two-way spoken conversation in Japanese. There are many special features in Japanese spoken conversation, such as particle omission, sentence-final particles, response tokens, fillers, repeat/repair and inversion. Being special characteristics of spoken Japanese, these features are indispensable to �natural� Japanese, and should be included in Japanese learning process if the goal of the Japanese education is to acquire natural Japanese. Despite their significance, these features have not sufficiently and systematically been taught in the current Japanese education. This is due to the fact that these features have not been recognised as formal learning objectives by Japanese teachers. However, there is no theoretical or empirical evidence that these features are too difficult for beginners and should not be taught at the elementary level. The study will discuss the curriculum development in the elementary courses of Japanese program at the Australian National University (ANU), which systematically adopts these features at the early stage of learning process. It will detail the development background, curriculum contents, and assessment of the special features. Since the curriculum was first implemented in the Japanese elementary courses at the ANU five years ago, no students or teachers have provided negative comments about learning/teaching these features. It is crucial that teachers first recognise those features as formal learning objectives and include in their Japanese courses

Demographic Change and the UK Savings Rate

We use microeconomic data to explore the effects of a changing age-structure on the UK's aggregate personal savings rate. Our findings suggest that changes to the population's age structure age have had detectable, sustained, but, relative to the yearly changes observed in the savings rate over the previous century, modest effects on aggregate personal sector savings. We estimate that the projected changes to the UK's age structure over the next 40 years are likely to raise the UK's savings rate but by no more than 2 percentage points. We find no basis for the view that the aggregate savings rate will decline as a result of the anticipated ageing of the UK population.Saving, ageing population

Cointegration-based tests of the New Keynesian Model of inflation

We show that the New-Keynesian (NK) model of inflation can be interpreted as a forward-looking cointegrated model. This allows us to model firms' expectations about marginal costs in a simple VAR framework and develop relatively simple formal tests of the model which bypass the econometric problems faced by other approaches. We show that a series of Granger-causality tests can indicate whether there is some forward-looking component to price setting. We implement these tests using quarterly data for the UK and the US. We find that the NK model is formally rejected but that there is strong evidence of a forward looking component to price setting.new-Keynesian, inflation, coeintegration