Investigation of Power Requirements for Ice Prevention and Cyclical De-Icing of Inlet Guide Vanes with Internal Electric Heaters

An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating. Heat-on periods in the order of 10 seconds with a cycle ratio of about 1:7 resulted in the best over-all performance with respect to total power requirements and aerodynamic losses during the heat-off period. Power requirements reported herein may be reduced by as much as 25 percent by achieving a more uniform surface-temperature distribution. A parameter in terms of engine mass flow, vane size, vane surface temperature, and the icing conditions ahead of the inlet guide vanes.was developed by which an extension of the experimental data to icing conditions and inlet guide vanes, other than those investigated was possible

NACA Research Memorandums

"An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating" (p. 1)

NACA Research Memorandums

"The results of an investigation of several internal water-inertia-separation inlets consisting of a main duct and an alternate duct designed to prevent automatically the entrance of large quantities of water into a turbojet engine in icing conditions are presented. Total-pressure losses and icing characteristics for a direct-ram inlet and the inertia-separation inlets are compared at similar aerodynamic and simulated icing conditions. Complete ice protection for inlet guide vanes could not be achieved with the inertia-separation inlets investigated" (p. 1)

Localizing the Charged Side Chains of Ion Channels within the Crowded Charge Models

The simplified coarse grained models of selectivity of Nonner and co-workers predict ion selectivity for a variety of different ion channels. The model includes the charged atoms of the channel’s charged residues and permeant ions. However its MC implementation does not take advantage of the increasingly large body of structural information available. Here, we introduce the location of the channel’s charged residues into the model’s Hamiltonian. In the DEKA Na+ channel, this allows us to correlate the lysine’s topological location directly with the predicted selectivity. In the NanC channel, from Escherichia coli, the dramatic variation in the resulting ion population predicts novel selectivity regions and binding sites that can be directly correlated with structural information. These results have well-defined thermodynamic properties that are significantly modified by structural detail allowing new insights with molecular detail