A numerical study of the effects of wind tunnel wall proximity on an airfoil model

A procedure was developed for modeling wind tunnel flows using computational fluid dynamics. Using this method, a numerical study was undertaken to explore the effects of solid wind tunnel wall proximity and Reynolds number on a two-dimensional airfoil model at low speed. Wind tunnel walls are located at varying wind tunnel height to airfoil chord ratios and the results are compared with freestream flow in the absence of wind tunnel walls. Discrepancies between the constrained and unconstrained flows can be attributed to the presence of the walls. Results are for a Mach Number of 0.25 at angles of attack through stall. A typical wind tunnel Reynolds number of 1,200,000 and full-scale flight Reynolds number of 6,000,000 were investigated. At this low Mach number, wind tunnel wall corrections to Mach number and angle of attack are supported. Reynolds number effects are seen to be a consideration in wind tunnel testing and wall interference correction methods. An unstructured grid Navier-Stokes code is used with a Baldwin-Lomax turbulence model. The numerical method is described since unstructured flow solvers present several difficulties and fundamental differences from structured grid codes, especially in the area of turbulence modeling and grid generation

The Syntax and Semantics of Wanting in Indonesian

The Indonesian verbs mau and ingin ‘want’ look like typical control verbs. When they are followed by a passive predicate however, an additional, unexpected interpretation arises. The sentence Siti mau/ingin di-cium oleh Ali means ‘Siti wants to be kissed by Ali’ but also ‘Ali wants to kiss Siti’. We call the latter interpretation Crossed Control (CC). In CC, the wanter is not the surface subject of ‘want’ but an oblique element in the complement clause and the surface subject is the theme of the embedded predicate and not an argument of ‘want’. For the syntax of CC, we reject clause union and backward control analyses and propose that ‘want’ in this construction is an auxiliary/raising verb that does not assign an external θ-role. We then propose that the control interpretation is encoded in the lexical semantics of the auxiliary. ‘Want’ takes a propositional argument but forces the volitional participant in this event to be construed as an experiencer of wanting. We hypothesize that this approach can be extended to volitional constructions in other languages.Linguistic

Against Covert A-Movement in Russian Unaccusatives

Linguistic

Malagasy Control and Its Theoretical Implications

Few syntactic phenomena have attracted as much attention as Control: a structure in which the overt subject of a dominating clause (the controller) determines the referential properties of an unpronounced subject of its complement clause (the controllee). More than thirty years of research, starting with Rosenbaum 1967, Postal 1970, and Bresnan 1972, have produced several interesting theories of Control and Raising (for a good summary of approaches, see Davies and Dubinsky 2004). At the same time, most studies of Control have built heavily on the facts of English and a small number of other well-studied languages. The goal of this paper is to investigate Control in Malagasy, an Austronesian language spoken in Madagascar that is significantly different from English. We will present and analyze three Subject Control constructions in Malagasy which may provide an argument in favor of a syntactic analysis of Control as movement (Hornstein 1999, 2003). The paper is structured as follows. Section 2 introduces basic facts of Malagasy grammar. Section 3 briefly surveys the contrasting syntactic approaches of Control that we consider. Sections 4 through 7 describe and analyze three different patterns of Control in Malagasy, using two of the patterns to argue for the movement analysis. Section 8 summarizes the results of this work.Linguistic

Expanding the Scope of Control and Raising

This paper presents unusual patterns in raising and control and offers a syntactic account which would validate such patterns. On the empirical side, we present evidence for backward control (data from several languages), backward raising (in Adyghe), copy control (Zapotec, Assamese, Tongan) and copy raising (data from a number of languages). All the unusual cases of raising and control seem to involve an A-movement chain in which the lower, not the higher copy is pronounced, or both copies are spelled out. We also review some constructions which, while superficially resembling backward or copy structure, do not provide any evidence for a movement chain. On the theoretical side, assuming that the more unusual patterns are an empirical reality, linguistic theory should be capable of analyzing them. We present mechanisms from the current Minimalist Program which we believe allow the attested variation.Linguistic

Large-scale structure formation for power spectra with broken scale invariance

We have simulated the formation of large-scale structure arising from COBE-normalized spectra computed by convolving a primordial double-inflation perturbation spectrum with the CDM transfer function. Due to the broken scale invariance ('BSI') characterizing the primordial perturbation spectrum, this model has less small-scale power than the (COBE-normalized) standard CDM model. The particle-mesh code (with $512^3$ cells and $256^3$ particles) includes a model for thermodynamic evolution of baryons in addition to the usual gravitational dynamics of dark matter. It provides an estimate of the local gas temperature. In particular, our galaxy-finding procedure seeks peaks in the distribution of gas that has cooled. It exploits the fact that ``cold" particles trace visible matter better than average and thus provides a natural biasing mechanism. The basic picture of large-scale structure formation in the BSI model is the familiar hierarchical clustering scenario. We obtain particle in cell statistics, the galaxy correlation function, the cluster abundance and the cluster-cluster correlation function and statistics for large and small scale velocity fields. We also report here on a semi-quantitative study of the distribution of gas in different temperature ranges. Based on confrontation with observations and comparison with standard CDM, we conclude that the BSI scenario could represent a promising modification of the CDM picture capable of describing many details of large-scale structure formation.Comment: 15 pages, Latex using mn.sty, uuencoded compressed ps-file with 15 figures by anonymous ftp to ftp://ftp.aip.de/incoming/mueller/bsi.u