Study of the structure of turbulent shear flows at supersonic speeds and high Reynolds number

A major effort to improve the accuracies of turbulence measurement techniques is described including the development and testing of constant temperature hot-wire anemometers which automatically compensate for frequency responses. Calibration and data acquisition techniques for normal and inclined wires operated in the constant temperature mode, flow geometries, and physical models to explain the observed behavior of flows are discussed, as well as cooperation with computational groups in the calculation of compression corner flows

Compressible turbulent boundary layer interaction experiments

Four phases of research results are reported: (1) experiments on the compressible turbulent boundary layer flow in a streamwise corner; (2) the two dimensional (2D) interaction of incident shock waves with a compressible turbulent boundary layer; (3) three dimensional (3D) shock/boundary layer interactions; and (4) cooperative experiments at Princeton and numerical computations at NASA-Ames

The Regional Greenhouse Gas Initiative: What It Means for Maine

The federal government has been slow to act on curbing greenhouse gas emissions that contribute to climate change and on reducing dependence on petroleum and other fossil fuels. In the absence of federal leadership, Maine and other states have enacted policies and practices to try to address these issues. Sondra Bogdonoff’s article discusses the 10-state Regional Greenhouse Gas Initiative (RGGI), in which Maine participates, the first regional program in the U.S. to address climate change. RGGI is a cap-and-trade system aimed at reducing CO2 emissions, which are “capped” at allowable levels. Power generators can buy and sell allowances. Under RGGI, each state must sell or auction off 25 percent of its allowances and use the proceeds to promote energy efficiency or new clean energy technologie

Consensus Building to Write Environmentally Responsive Rules for Maine\u27s New Transportation Policy

The writing of Maine\u27s transportation policy represents an innovative approach to broad based citizen participation in a policy arena (transportation) where public involvement has traditionally been limited. Through consensus building and shared stakeholder power, environmental concerns were integrated into transportation policy planning at the state level. The process offers a possible alternative to the gridlock and high expense associated with the use of litigation to resolve conflict

BEI\u27s Driver Skill Enhancement Program (D-SEP): Brief Review of Experimental Mini-Program and Conclusions

The program had its beginnings in a local group meeting to provide input to the “White House Commission on Aging”, about 6 years ago. At this meeting, the author became acutely aware of the problems older people had with driving. Building on the author’s twenty-five years of activities with “Drivers Education” programs on high-speed road tracks, Ref. 1, he started a research program, which continues today. Research was initiated into other driving schools and their methods, and study of the fundamental elements of driving (from many sources). The research was supplemented by data gathering on the “process of driving” (by discussions with many “experts”). There is general agreement that driving is a combination of several skills; and there are three basic elements of driving: a) information gathering, primarily visual b) cognitive processing, during which the large amount of data obtained visually is sifted to separate out what is crucial for the driving experience. A decision is made as to what should be done. c) physical activities of the arms and legs, to carry out the decisions reached in the cognitive process. This process is repeated continuously as one drives, since driving is a “dynamic” process. The BEI program is based on two premises: 1) P+A=a good driver. P is Preparation: what the drivers, in their cars, can actually do. A is Anticipation: the visual-cognitive process which buys time to carry out the physical activities involved in making a car perform. Anticipation is usually not consciously practiced, although carried out in some form, for all driving. 2) “Training and practice” will, in most cases, considerably enhance the skills required for driving

A Primer for Maine: Regional Greenhouse Gas Initiative

This primer is designed to provide Maine citizens with a basic understanding of the program and the key decisions Maine must make in the implementation of the Regional Greenhouse Gas Initiative

Wind-Tunnel Investigation of a Low-Drag Airfoil Section with a Double Slotted Flap

Tests were made of an 0.309-chord double-slotted flap on an NACA 65, 3-118, a equals 1.0 airfoil section to determine drag, lift, and pitching-moment characteristics for a range of flap deflections. Results indicate that combination of a low-drag airfoil and a double-slotted flap, of which the two parts moved as a single unit, gave higher maximum lift coefficients than have been obtained with plain, split, or slotted flaps on low-drag airfoils. Pitching moments were comparable to those obtained with other high-lift devices on conventional airfoils for similar lift coefficients

Exploratory study of in-plane streamline curvature effects on a turbulent boundary layer at a Mach number of 3

This report on a program to study in-plane streamline curvature effects in a turbulent boundary layer at a Mach number of 3. The original proposal, for a 3-year program to explore in-plane streamline curvature effects on a supersonic turbulent boundary layer using three-dimensional pressure fields generated by fins and wall geometry, ended after one year. The purpose of these tests was to compare these streamline curvature effects to the more classical two-dimensional curvature generated by wall shape and imposed pressure gradients, previously considered primarily in a plane normal to the floor. The studies were carried out in the Mach number of 3, 8 x 8 inch High Reynolds Number Supersonic Tunnel. The usual surface visualization and mean wall static pressures were supplemented by the use of many small high frequency wall static pressure gauges (Kulites) to get some indication of the amplification of boundary layer disturbances by the in-plane streamline curvature caused by the three-dimensional pressure fields imposed on the boundary layer