Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
In order to extend the range of available planing-surface data, the hydrodynamic characteristics have been obtained for a planing surface having a basic angle of dead rise of 200 at the keel and horizontal chine flare. This surface is representative of those used on present day flying boats. The wetted lengths, resistances, center-of-pressure locations, and drafts were determined at speed coefficients (Froude numbers) ranging from approximately 3.0 to 25.0, with the bulk of the data obtained at Froude numbers in excess of 7.0. Beam loadings were varied from 0.85 to 87.33. Keel-wetted-length-beam ratios were extended to 7.0 in all cases where excessive loads and spray conditions were not encountered. The data obtained indicate that, during high-speed steady-state planing, the planing characteristics are independent of speed and load for a given trim and depend only on lift coefficient. The difference between the chine wetted length and keel wetted length is constant for a given trim angle and the variation of this difference with trim is shown to be in reasonable agreement with theory. The ratio of center-of-pressure location forward of the step to the mean wetted length, for practical applications, can be considered a constant equal to 0.67 up to 180 of trim. A slight decrease in this ratio occurs with further increase in trim angle. The draft data indicate a pile-up of water at the keel during steady-state planing. Although negligible at low trims, this pile-up was significant at trims of 12 deg and higher. The drag data show that friction drag at trims of 18 deg and higher is negligible and that the resistances for those trims may be assumed equal to the load times the tangent of the trim angle.
The Planing Characteristics of a Surface Having a Basic Angle of Dead Rise of 20 Deg. and Horizontal Chine Flare
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
In order to extend the range of available planing-surface data, the hydrodynamic characteristics have been obtained for a planing surface having a basic angle of dead rise of 200 at the keel and horizontal chine flare. This surface is representative of those used on present day flying boats. The wetted lengths, resistances, center-of-pressure locations, and drafts were determined at speed coefficients (Froude numbers) ranging from approximately 3.0 to 25.0, with the bulk of the data obtained at Froude numbers in excess of 7.0. Beam loadings were varied from 0.85 to 87.33. Keel-wetted-length-beam ratios were extended to 7.0 in all cases where excessive loads and spray conditions were not encountered. The data obtained indicate that, during high-speed steady-state planing, the planing characteristics are independent of speed and load for a given trim and depend only on lift coefficient. The difference between the chine wetted length and keel wetted length is constant for a given trim angle and the variation of this difference with trim is shown to be in reasonable agreement with theory. The ratio of center-of-pressure location forward of the step to the mean wetted length, for practical applications, can be considered a constant equal to 0.67 up to 180 of trim. A slight decrease in this ratio occurs with further increase in trim angle. The draft data indicate a pile-up of water at the keel during steady-state planing. Although negligible at low trims, this pile-up was significant at trims of 12 deg and higher. The drag data show that friction drag at trims of 18 deg and higher is negligible and that the resistances for those trims may be assumed equal to the load times the tangent of the trim angle.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
In order to extend the range of available planing-surface data, the hydrodynamic characteristics have been obtained for a planing surface having a basic angle of dead rise of 200 at the keel and horizontal chine flare. This surface is representative of those used on present day flying boats. The wetted lengths, resistances, center-of-pressure locations, and drafts were determined at speed coefficients (Froude numbers) ranging from approximately 3.0 to 25.0, with the bulk of the data obtained at Froude numbers in excess of 7.0. Beam loadings were varied from 0.85 to 87.33. Keel-wetted-length-beam ratios were extended to 7.0 in all cases where excessive loads and spray conditions were not encountered. The data obtained indicate that, during high-speed steady-state planing, the planing characteristics are independent of speed and load for a given trim and depend only on lift coefficient. The difference between the chine wetted length and keel wetted length is constant for a given trim angle and the variation of this difference with trim is shown to be in reasonable agreement with theory. The ratio of center-of-pressure location forward of the step to the mean wetted length, for practical applications, can be considered a constant equal to 0.67 up to 180 of trim. A slight decrease in this ratio occurs with further increase in trim angle. The draft data indicate a pile-up of water at the keel during steady-state planing. Although negligible at low trims, this pile-up was significant at trims of 12 deg and higher. The drag data show that friction drag at trims of 18 deg and higher is negligible and that the resistances for those trims may be assumed equal to the load times the tangent of the trim angle.
The Planing Characteristics of a Surface Having a Basic Angle of Dead Rise of 20° and Horizontal Chine Flare
The Planing Characteristics of a Surface Having a Basic Angle of Dead Rise of 20 Degrees and Horizontal Chine Flare
Author: Walter J. Kapryan
Publisher:
ISBN:
Category : Planing hulls
Languages : en
Pages : 42
Book Description
A high-speed investigation was conducted to determine the hydrodynamic characteristics of a planing suface having an angle of dead rise of 20 degrees and horizontal chine flare. The data indicate that the planing characteristics at a given trim depend only on lift coefficient. The ration of center-of-pressure location to the mean wetted length can be considered approximately equal to 0.67 up to 18 degrees of trim. This ratio decreases with further increase in trim. Pile-up of water at the keep of the model was substantial at trims above 12 degrees. Friction drag is negligible at high trims. The resistances for trims at 18 degrees and higher, therefore, may be assumed equal to the load times the tangent of the trim angle.
Publisher:
ISBN:
Category : Planing hulls
Languages : en
Pages : 42
Book Description
A high-speed investigation was conducted to determine the hydrodynamic characteristics of a planing suface having an angle of dead rise of 20 degrees and horizontal chine flare. The data indicate that the planing characteristics at a given trim depend only on lift coefficient. The ration of center-of-pressure location to the mean wetted length can be considered approximately equal to 0.67 up to 18 degrees of trim. This ratio decreases with further increase in trim. Pile-up of water at the keep of the model was substantial at trims above 12 degrees. Friction drag is negligible at high trims. The resistances for trims at 18 degrees and higher, therefore, may be assumed equal to the load times the tangent of the trim angle.
The Planing Characteristics of a Surface Having a Basic Angle of Dead Angle Rise of 40 Degrees and Horizontal Chine Flare
Author: Ulysse J. Blanchard
Publisher:
ISBN:
Category : Friction
Languages : en
Pages : 26
Book Description
The principal characteristics of an surface having an angle of dead rise of 40 degrees and horizontal chine flare are presented. The data indicated that at a given trim the important planing characteristics depend mainly on lift coefficient. The effects of increasing the basic angle of dead rise from 20 degrees (NACA TN 2804) to 40 degrees are to decrease the ratio of the center-to-pressure location to the mean wetted length, to decrease the extent of pile-up of water at the keel, and to increase the friction drag.
Publisher:
ISBN:
Category : Friction
Languages : en
Pages : 26
Book Description
The principal characteristics of an surface having an angle of dead rise of 40 degrees and horizontal chine flare are presented. The data indicated that at a given trim the important planing characteristics depend mainly on lift coefficient. The effects of increasing the basic angle of dead rise from 20 degrees (NACA TN 2804) to 40 degrees are to decrease the ratio of the center-to-pressure location to the mean wetted length, to decrease the extent of pile-up of water at the keel, and to increase the friction drag.
Hydrodynamic Characteristics of a Planing Surface with Convex Longitudinal Curvature and an Angle of Dead Rise of 20 Degrees
Author: Elmo J. Mottard
Publisher:
ISBN:
Category : Hydrodynamics
Languages : en
Pages : 32
Book Description
Publisher:
ISBN:
Category : Hydrodynamics
Languages : en
Pages : 32
Book Description
An Approximate Method of Calculating the Deformations of Wings Having Swept, M Or W, Lambda, and Swept-tip Plan Forms
Author: George W. Zender
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 692
Book Description
An approximate method of calculating the deformation of wings of uniform thickness having swept, M or W, Lambda, and swept-tip plan forms is presented. The method employs an adjustment to the elementary beam theory to account for the effect of the triangular root portion portion of a swept wing on the deformation of the outboard section of the wing. To demonstrate the general applicability of the method, the modified elementary theory is applied to the more comples M or W, Lambda, and swept-tip plan forms as well as to swept plan forms. For the purpose of calculating angles of attack, it is shown that the unmodified elementary beam theory applied to that part of the wing outboard of the root triangle produces satisfactory results. However, for calculating deflections it is necessary to include the effects of the root-triangle deformation.
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 692
Book Description
An approximate method of calculating the deformation of wings of uniform thickness having swept, M or W, Lambda, and swept-tip plan forms is presented. The method employs an adjustment to the elementary beam theory to account for the effect of the triangular root portion portion of a swept wing on the deformation of the outboard section of the wing. To demonstrate the general applicability of the method, the modified elementary theory is applied to the more comples M or W, Lambda, and swept-tip plan forms as well as to swept plan forms. For the purpose of calculating angles of attack, it is shown that the unmodified elementary beam theory applied to that part of the wing outboard of the root triangle produces satisfactory results. However, for calculating deflections it is necessary to include the effects of the root-triangle deformation.
Icing Protection for a Turboject Transport Airplane: Heating Requirements, Methods of Protection, and Performance Penalties
Author: Thomas F. Gelder
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 740
Book Description
The heating requirements for several methods of icing protection for a typical turbojet transport airplane operating over a probable range of icing conditions are evaluated, and the airplane performance penalties associated with providing this protection from various energy source are assessed. Continuous heating requirements and airplane penalties for the turbojet transport are considered considerably increased over those for lower-speed aircraft. Heating requirements can be substantially reduced by use of a cyclic de-icing system and choice of the proper energy source.
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 740
Book Description
The heating requirements for several methods of icing protection for a typical turbojet transport airplane operating over a probable range of icing conditions are evaluated, and the airplane performance penalties associated with providing this protection from various energy source are assessed. Continuous heating requirements and airplane penalties for the turbojet transport are considered considerably increased over those for lower-speed aircraft. Heating requirements can be substantially reduced by use of a cyclic de-icing system and choice of the proper energy source.
Annual Report of the National Advisory Committee for Aeronautics
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 872
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 872
Book Description
Report
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 56
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 56
Book Description