Experimental study of surface pressures induced on a flat plate and a body of revolution by various dual jet configurations

The effect of the angle of a jet to a crossflow, the performance of dual jet configurations, and a jet injected from a body of revolution as opposed to a flat plate were investigated during experiments conducted in the 7x10 tunnel at NASA Ames at Velocities from 14.5 m/sec to 35.8 m/sec (47.6 to 117.4 ft/sec.). Pressure distributions are presented for single and dual jets over a range of velocity ratios from 2 to 10, spacings from 2 to 6 diameters and injection angles of 90, 75, 60, and 105 degrees. For the body of revolution tests, the ratio of the jet to body diameters was set as large (1/2) in order to be more representative of V/STOL aircraft applications. Flat plate tests involved dual jets both aligned and in side by side configurations. The effects of the various parameters and the differences between the axisymmetric and planar body geometrics on the nature, size, shape, and strength of the interaction regions on the body surfaces are shown. Some flowfield measurements are also presented, and it is shown that a simple analysis is capable of predicting the trajectories of the jets

Heat-transfer and pressure distributions for laminar separated flows downstream of rearward-facing steps with and without mass suction

Heat-transfer and pressure distributions were measured for laminar separated flows downstream of rearward-facing steps with and without mass suction. The flow conditions were such that the boundary-layer thickness was comparable to or larger than the step height. For both suction and no-suction cases, an increase in the step height resulted in a sharp decrease in the initial heat-transfer rates behind the step. Downstream, however, the heat transfer gradually recovered back to less than or near attached-flow values. Mass suction from the step base area increased the local heat-transfer rates; however, this effect was relatively weak for the laminar flows considered. Even removal of the entire approaching boundary layer raised the post-step heat-transfer rates only about 10 percent above the flatplate values. Post-step pressure distributions were found to depend on the entrainment conditions at separation. In the case of the solid-faced step, a sharp pressure drop behind the step was followed by a very short plateau and relatively fast recompression. For the slotted-step connected to a large plenum but without suction, the pressure drop at the base was much smaller and the downstream recompression more gradual than that for solid-faced step

Rearward-facing steps in laminar supersonic flows with and without suction

An experimental investigation of heat-transfer and pressure distributions within regions of laminar separated flows produced by two-dimensional rearward-facing steps has been carried out at freestream Mach numbers of around 4 in the range of step height-to-boundary layer thickness varying from 0.1 to 2.4. With no suction from the separated area, the ratio of the maximum post-step heat transfer to the attached-flow values was less than unity. The maximum heating-rate region was located far downstream of the reattachment plate stagnation point. Mass suction from the separated area increased the local heating rates, this effect was however relatively weak for purely laminar flow conditions and the competing effect of the step height clearly predominated. At step heights comparable with boundary-layer thickness, even removing the entire approaching boundary layer was not sufficient to raise the post-step heating rates above the flat-plate values

Implicit communication : the body\u27s role in clinical work with trauma survivors

This exploratory-descriptive study examined therapists\u27 use of their physiological responses in work with trauma survivors. Broadly, the study sought to understand how a therapist\u27s physiological responses play a role in how they construct meaning about a client. The study sample consisted of eight Relationally oriented therapists who worked with trauma survivors. Data were collected through hour-long, semi-structured interviews with each participant at a single point in time, utilizing the Physiological Response to Trauma Questionnaire. Findings revealed that participants used their physiological countertransference to inform clinical functions, specifically: ability to attune, choice of interventions, assessment, and ability to maintain boundaries and prevent vicarious trauma

Effects of velocity profile and inclination on dual-jet-induced pressures on a flat plate in a crosswind

An experimental study was conducted to determine surface pressure distributions on a flat plate with dual subsonic, circular jets exhausting from the surface into a crossflow. The jets were arranged in both side-by-side and tandem configurations and were injected at 90 deg and 60 deg angles to the plate, with jet-to-crossflow velocity ratio of 2.2 and 4. The major objective of the study was to determine the effect of a nonuniform (vs uniform) jet velocity profile, simulating the exhaust of a turbo-fan engine. Nonuniform jets with a high-velocity outer annulus and a low-velocity core induced stronger negative pressure fields than uniform jets with the same mass flow rate. However, nondimensional lift losses (lift loss/jet thrust lift) due to such nonuniform jets were lower than lift losses due to uniform jets. Changing the injection angle from 90 deg to 60 deg resulted in moderate (for tandem jets) to significant (for side-by-side jets) increases in the induced negative pressures, even though the surface area influenced by the jets tended to reduce as the angle decreased. Jets arranged in the side-by-side configuration led to significant jet-induced lift losses exceeding, in some cases, lift losses reported for single jets

Inviscid Large deviation principle and the 2D Navier Stokes equations with a free boundary condition

Using a weak convergence approach, we prove a LPD for the solution of 2D stochastic Navier Stokes equations when the viscosity converges to 0 and the noise intensity is multiplied by the square root of the viscosity. Unlike previous results on LDP for hydrodynamical models, the weak convergence is proven by tightness properties of the distribution of the solution in appropriate functional spaces

Transnational tourist destination management: a case study of the Baltic sea region

The issue of tourist destination management has been widely reflected in scientific literature. However, transnational destinations, i.e. those that are located on the territory of several countries, have not been given enough attention. The development of transnational destinations can occur provided there is close cooperation among key stakeholders. In the Baltic Sea Region (BSR) conditions for effective cooperation were created at the end of the 20th century when integration processes intensified. Currently, the BSR is the first macro-region of the European Union to implement a transnational strategy, in which tourism is recognised as a development priority. Creating an effective tourist destination management system has become a key challenge in this process. This article aims to identify and critically analyse the concept of transnational tourist destination management. Another goal is to identify the changing determinants of tourism management in the BSR and to explore relations between key stakeholders. To this end, we conducted a review of literature on destination management. We carried out a critical analysis of secondary sources (documents, information materials, the Internet resources) and supplemented the review with our insights from participatory observation. We also obtained additional information from interviews. Three models of destination management were identified: marketing-oriented, planning-oriented, and governance-oriented. Our research shows that the evolution of destination management is characterised by a gradual increase in the participation of public entities. This is related to the marginalisation of the tourism industry, which resulted in a systematic decrease in state funding for maintaining destination management structures. Acquiring the European Union funds from the European Territorial Cooperation Programs has become a partial but not entirely effective solution to this problem

PARAS program: Phased array radio astronomy from space

An orbiting radio telescope is proposed which, when operated in a Very Long Baseline Interferometry (VLBLI) scheme, would allow higher (than currently available) angular resolution and dynamic range in the maps, and the ability of observing rapidly changing astronomical sources. Using a passive phases array technology, the proposed design consists of 656 hexagonal modules forming a 150 meter diameter dish. Each observatory module is largely autonomous, having its own photovoltaic power supply and low-noise receiver and processor for phase shifting. The signals received by the modules are channeled via fiber optics to the central control computer in the central bus module. After processing and multiplexing, the data is transmitted to telemetry stations on the ground. The truss frame supporting each observatory pane is a hybrid structure consisting of a bottom graphite/epoxy tubular triangle and rigidized inflatable Kevlar tubes connecting the top observatory panel and bottom triangle. Attitude control and stationkeeping functions are performed by a system of momentum wheels in the bus and four propulsion modules located at the compass points on the periphery of the observatory dish. Each propulsion module has four monopropellant thrusters and six hydrazine arcjets, the latter supported by a nuclear reactor. The total mass of the spacecraft is 22,060 kg

Soliton X-junctions with controllable transmission

We propose new planar X-junctions and multi-port devices written by spatial solitons, which are composed of two (or more) nonlinearly coupled components in Kerr-type media. Such devices have no radiation losses at a given wavelength. We demonstrate that, for the same relative angle between the channels of the X-junctions, one can vary the transmission coefficients into the output channels by adjusting the polarizations of multi-component solitons. We determine analytically the transmission properties and suggest two types of experimental embodiments of the proposed device.Comment: 3 pages, 2 figure

The Health of Immigrants to New York City From Mainland China: Evidence From the New York Health Examination and Nutrition Survey

Very little is known about the newest New Yorkers of Chinese heritage, the largest and fastest growing immigrant group in the city. This article compares measures of the health of immigrants to New York from Mainland China to the health of other New Yorkers of Asian heritage along with all other New Yorkers. We did so using the 1,999 subjects in the 2004 New York Health and Nutrition Examination Survey, controlling for age and gender. We found that New Yorkers born in Mainland China have a lower body mass index, a smaller waist circumference, a more sexually conservative lifestyle, highly favorable high-density lipoprotein profiles, and lower rates of herpes II infection. However, they also have higher blood levels of lead, cadmium, and mercury than either reference group. This article provides the first study of the health needs of New York's largest and most rapidly growing immigrant group