Analysis and performance prediction of scramjet inlets utilizing a three-dimensional Navier-Stokes code

A series of inlet analysis codes (2-D, axisymmetric, 3-D) were developed which can analyze complicated flow through complex inlet geometries in a reasonably efficient manner. The codes were verified and are being used extensively to analyze practical inlet geometries both at Langley as well as industries. Newly installed VPS 32 computer will allow more complex configurations to be analyzed. Scalar FORTRAN versions are available to increase transportability of the codes for use on other Scalar computers and on the Cray vector processing computer

Hofstede’s Cultural Dimensions and Tourist Behaviors: A Review and Conceptual Framework

This paper develops a conceptual framework for analyzing tourist behaviors and identifies three categories of behaviors based on the applications of Hofstede’s cultural dimensions and the processes underlying these influences. Our findings indicate that tourist behaviors in the Before-Travel, During-Travel, and After-Travel stages differ significantly in terms of the applicability and process through which Hofstede’s cultural dimensions operate. The results of our analysis suggest three categories of behavioral patterns, namely, “Social Interaction Driven Travel Behaviors,” (SID), “Risk Tendencies Driven Travel Behaviors,” (RTD), and “Collectivity Orientation Driven Travel Behaviors,” (COD). SID relates to the evaluation of travel experiences in the after-travel stage. The dominant cultural values associated with SID are Individualism/Collectivism, Masculinity/Femininity, and Power Distance. These three values act either independently or in pairs or all three together. RTD relates to the consumption of travel products in the during-travel stage, and COD relates to the formation of travel preferences in the before-travel stage. Individualism/Collectivism and Uncertainty Avoidance are associated with both RTD and COD. However, the underlying processes differ for these two categories of travel behaviors. In addition to their independent influences on travel behaviors, these two values associated with RTD and COD also have an interactive effect. For RTD, the Uncertainty Avoidance motive determines the Individualism/Collectivism outcome, whereas, for COD, the opposite is true: the Individualism/Collectivism determines the Uncertainty Avoidance outcome. The paper also discusses the application of a fifth cultural dimension, Confucian Dynamism (short-term versus long-term orientation), for the study of tourists’ behaviors.Hofstede’s cultural dimensions; tourist behaviors; traveller’s behaviors; Confucian Dynamism

Finite element thermo-viscoplastic analysis of aerospace structures

The time-dependent thermo-viscoplastic response of aerospace structures subjected to intense aerothermal loads is predicted using the finite-element method. The finite-element analysis uses the Bodner-Partom unified viscoplastic constitutive relations to determine rate-dependent nonlinear material behavior. The methodology is verified by comparison with experimental data and other numerical results for a uniaxially-loaded bar. The method is then used (1) to predict the structural response of a rectangular plate subjected to line heating along a centerline, and (2) to predict the thermal-structural response of a convectively-cooled engine cowl leading edge subjected to aerodynamic shock-shock interference heating. Compared to linear elastic analysis, the viscoplastic analysis results in lower peak stresses and regions of plastic deformations

Rare Earth Doping and Effective Band-Convergence in SnTe for Improved Thermoelectric Performance

Thermoelectric performance of SnTe has been found to enhance with isovalent doping of alkaline and transition metal elements where most of these elements have solubility of less than 13%. We propose a strategy of doping rare earth element Yb to enhance the thermoelectric performance of SnTe. With heavy atomic mass and strong spin-orbit coupling, even the mild doping of Yb (~ 5%) is enough to create a degeneracy via band-convergence which enhances the density of states near Fermi level and improve overall performance. Our transport data and first-principles calculations corroborate that nearly 5% Yb is an efficient dopant to achieve thermoelectric response which is equivalent to 9% of Mn doping. The results are useful for understanding the environment-friendly thermoelectric SnTe

Selection of Dominant Characteristic Modes

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The theory of characteristic modes is a popular physics based deterministic approach which has found several recent applications in the fields of radiator design, electromagnetic interference modelling and radiated emission analysis. The modal theory is based on the approximation of the total induced current in an electromagnetic structure in terms of a weighted sum of multiple characteristic current modes. The resultant outgoing field is also a weighted summation of the characteristic field patterns. Henceforth, a proper modal measure is an essential requirement to identify the modes which play a dominant role for a frequency of interest. The existing literature of significance measures restricts itself for ideal lossless structures only. This paper explores the pros and cons of the existing measures and correspondingly suggests suitable alternatives for both radiating and scattering applications. An example is presented in order to illustrate the proposed modal method for approximating the shielding response of a slotted geometry