NASA's Aircraft Icing Analysis Program

An overview of the NASA ongoing efforts to develop an aircraft icing analysis capability is presented. Discussions are included of the overall and long term objectives of the program as well as current capabilities and limitations of the various computer codes being developed. Descriptions are given of codes being developed to analyze two and three dimensional trajectories of water droplets, airfoil ice accretion, aerodynamic performance degradation of components and complete aircraft configurations, electrothermal deicer, fluid freezing point depressant antideicer and electro-impulse deicer. The need for bench mark and verification data to support the code development is also discussed, and selected results of experimental programs are presented

Operating characteristics of an inlet model tested with a 0.5m powered fan at high angles of attack

An inlet model designed for high angle of attack capability, coupled to a .508 m tip diameter turbofan simulator, was tested in the NASA-Lewis Research Center's 9-by 15-ft low speed wind tunnel. The test variables were: tunnel velocity, 0 to 75 m/s; inlet angle of attack, 0 to 120 deg; and fan face corrected airflow per unit area, 75 to 200 kg/s sqm. The inlet flow separation boundaries, the fan face total pressure recovery and distortion characteristics, and the fan blade vibratory stresses were determined. The recovery, distortion, and stress levels showed no abrupt changes at the onset of separation, but became gradually more unfavorable as the size and intensity of the separation increased as induced by increasingly severe operating conditions. Performance characteristics for a large scale model of the inlet were estimated from these test results

Colour Dipoles and Saturation

We employ values of the colour dipole cross section extracted from electroproduction and photoproduction data to show that gluon saturation effects are not required by the current HERA data but will become important in the THERA energy region.Comment: 3 pages, 2 figures. Talk given by G.S. at DIS 2000(Liverpool, April 2000

Massive neutrinos and magnetic fields in the early universe

Primordial magnetic fields and massive neutrinos can leave an interesting signal in the CMB temperature and polarization. We perform a systematic analysis of general perturbations in the radiation-dominated universe, accounting for any primordial magnetic field and including leading-order effects of the neutrino mass. We show that massive neutrinos qualitatively change the large-scale perturbations sourced by magnetic fields, but that the effect is much smaller than previously claimed. We calculate the CMB power spectra sourced by inhomogeneous primordial magnetic fields, from before and after neutrino decoupling, including scalar, vector and tensor modes, and consistently modeling the correlation between the density and anisotropic stress sources. In an appendix we present general series solutions for the possible regular primordial perturbations

Depositing spacing layers on magnetic film with liquid phase epitaxy

Liquid phase epitaxy spacing layer is compatible with systems which are hard-bubble proofed by use of second magnetic garnet film as capping layer. Composite is superior in that: circuit fabrication time is reduced; adherence is superior; visibility is better; and, good match of thermal expansion coefficients is provided

Ice shapes and the resulting drag increase for a NACA 0012 airfoil

Experimental measurements of the ice shapes and resulting drag increases were measured in the NASA-Lewis Icing Research Tunnel. The measurements were made over a large range of conditions (e.g., airspeed and temperature, drop size and liquid water content of the cloud, and the angle of attack of the airfoil). The measured drag increase did not agree with the existing correlation. Additional results were given which are helpful in understanding the ice structure and the way it forms, and in improving the ice accretion modeling theories. There are data on the ice surface roughness, on the effect of the ice shape on the local droplet catch, and on the relative importance of various parts of the ice shape on the drag increase. Experimental repeatability is also discussed

The UH-1H helicopter icing flight test program: An overview

An ongoing joint NASA/Army program to study the effects of ice accretion on unprotected helicopter rotor aerodynamic performance is discussed. This program integrates flight testing, wind tunnel testing, and analytical modeling. Results are discussed for helicopter flight testing in the Canadian NRC hover spray rig facility to measure rotor aero performance degradation and document rotor ice accretion characteristics. The results of dry wind tunnel testing of airfoil sections with artificial ice accretions and predictions of rotor performance degradation using available rotor performance codes and the wind tunnel data are presented. An alternative approach to conducting future helicopter icing flight programs is discussed

The determinants of receiving social care in later life in England

Demographic change and policy changes in social care provision can affect the type of social care support received by older people, whether through informal, formal state or formal paid-for sources. This paper analyses the English Longitudinal Study of Ageing data (wave 4) in order to examine the relationship between demographic and socio-economic characteristics, and the receipt of support from different sources by older people who report difficulty with daily activities. The research outlines three key results with implications for the future organisation of social care for older people. Firstly, the number of instrumental activities of daily living (IADLs) an older person reports having difficulty with, followed by the number of activities of daily living (ADLs) are the strongest determinants of receiving support from any source. Secondly, there are significant gender differences in the factors associated with receiving support from different sources; for example, physical health is a strong determinant of informal support receipt by men, while mental health status is a strong determinant of informal support receipt by women. Finally, the research shows that different kinds of impediments in everyday life are associated with receiving support from different sources. This ‘link’ between particular types of difficulties and support receipt from particular sources raises questions about the way social care provision can or should be organised in the future