Systems and methods for modifying an ice-to-object interface

• US 20030155467A1
• Filed: 02/11/2003
• Published: 08/21/2003
• Est. Priority Date: 02/11/2002
• Status: Active Grant

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Petrenko, Victor
• Granted Patent: US 6,870,139 B2
• Time in Patent Office: Days
• US Class Current: 244/134R
• CPC Class Codes: A63C 1/30 with special blades
• CPC Class Codes: A63C 2203/12 Electrically powered or heated
• CPC Class Codes: A63C 3/00 Accessories for skates
• CPC Class Codes: A63C 5/06 with special devices thereon, e.g. steering devices
• CPC Class Codes: B64D 15/12 by electric heating electric heating elements in general H05B
• CPC Class Codes: B64D 15/14 controlled cyclically along length of surface
• CPC Class Codes: B64D 15/22 Automatic initiation by icing detector
• CPC Class Codes: F01D 25/02 De-icing means for engines having icing phenomena
• CPC Class Codes: F02C 7/047 Heating to prevent icing
• CPC Class Codes: F25C 5/08 by heating bodies in contact with the ice
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Systems and methods for thermally modifying an ice-to-object interface. One system includes a power supply configured to generate a magnitude of power. The magnitude of the power is sufficient to melt an interfacial layer of ice at the interface; typically the interfacial layer has a thickness in a range one micron to one millimeter. A controller may be used to limit the duration in which power supply generates the magnitude of the power, to limit unneeded heat energy dissipation into the environment. Modulating the pulsed heating energy to the interface modifies a coefficient of friction between the object and the ice.

Claims

1. A method of thermally modifying an interface between ice and an object, comprising the steps of:

applying heating energy to the interface to melt an interfacial layer of ice; and

limiting duration of the step of applying heating energy to the interface such that the heating energy has a heat diffusion distance within the ice that extends no more than through the thickness of the interfacial layer of ice.

2. The method of claim 1, wherein the step of applying heating energy comprises the step of applying power at the interface with a magnitude that is at least about inverse proportional to a magnitude of energy used to melt the interfacial layer of ice.

3. The method of claim 2, wherein the step of limiting duration comprises the step of limiting duration of the step of applying power at the interface such that the duration is at least about inverse proportional to a square of the magnitude of the power.

4. The method of claim 1, wherein the step of applying heating energy comprises the step of applying power to the interface with a magnitude that is substantially inverse proportion to a magnitude of energy used to melt the interfacial ice, and wherein the step of limiting duration comprises the step of limiting the duration so that the duration is substantially inverse proportion to a square of the magnitude of the power.

5. The method of claim 1, further comprising the step of facilitating refreezing of the interfacial layer of the ice to affect a coefficient of friction between the object and the ice.

6. The method of claim 5, the step of facilitating comprising one or more of the following steps:

(1) waiting for refreezing after the step of limiting duration;

(2) blowing cold air at the interface; and

(3) misting water at the interface.

7. The method of claim 1, the object selected from the group of an aircraft structure, a windshield, a mirror, a headlight, a power line, a ski lift structure, a rotor surface of a windmill, a rotor surface of a helicopter, a roof, a deck, a building structure, a road, a bridge structure, a freezer structure, an antenna, a satellite, a railroad structure, a tunnel structure, a cable, a road sign, a snowshoe, a ski, a snowboard, a skate, and a shoe.

8. The method of claim 1, wherein the step of applying heating energy to the interface comprises applying heating energy to the interface to melt an interfacial layer of ice having a thickness that is less than about five centimeters.

9. The method of claim 1, wherein the step of applying heating energy to the interface comprises applying heating energy to the interface to melt an interfacial layer of ice having a thickness that is less than about one millimeter.

10. The method of claim 1, wherein the step of applying heating energy to the interface comprises applying heating energy to the interface to melt an interfacial layer of ice having a thickness that is between about one micron and one millimeter.

11. The method of claim 1, wherein the step of limiting duration of the step of applying heating energy to the interface comprises the step of applying heating energy to the interface for a maximum of 100 s.

12. The method of claim 1, wherein the step of applying heating energy to the interface comprises the step of applying power to a heating element in thermal communication with the interface.

13. The method of claim 12, wheren the step of applying heating energy to the interface comprises the step of applying power to a heating element within the object.

14. The method of claim 12, wherein the step of applying heating energy to the interface comprises the step of applying power to a heating element at a surface of the object and in contact with the interface.

15. The method of claim 12, wherein the step of applying heating energy to the interface comprises the step of electrically resisting the power with the heating element.

16. The method of claim 12, wherein the step of limiting duration comprises the step of controlling duration of the step of applying power according to the following relationship:

17. The method of claim 12, wherein the step of applying power comprises the step of controlling energy according to the following relationship:

18. The method of claim 12, wherein the step of applying power comprises the step of controlling energy according to the following relationship:

19. The method of claim 1, further comprising the step of repeating the steps of applying and limiting in a periodic manner to generate a desired coefficient of friction between the object and the ice.

20. The method of claim 1, the step of limiting duration comprising the step of limiting the duration to between about 1 ms to 10 s.

21. The method of claim 1, further comprising reapplying power at the interface after the interfacial layer refreezes to selectively control a coefficient of friction between the ice and the object while the object moves over the ice.

22. The method of claim 1, the ice comprising snow.

23. The method of claim 1, the object comprising a slider.

24. The method of claim 23, the slider comprising one of a shoe, a snowboard, and a ski.

25. A method for controlling a coefficient of friction between an object and ice, comprising the steps of:

(1) pulsing power to an interface between the object and the ice to melt an interfacial layer of ice at the interface and decrease the coefficient of friction;

(2) facilitating refreezing of the interfacial ice at the interface to increase the coefficient of friction; and

(3) repeating steps (1) and (2) in a controllable manner to control an average coefficient of friction between the object and the ice.

26. The method of claim 25, the step of facilitating refreezing comprising the step of moving the object over the ice to decrease temeprature of the object.

27. The method of claim 25, the step of pulsing power comprising the steps of blowing first air onto the object, the first air having a temperature above freezing, and moving the object in contact with the ice.

28. The method of claim 27, the object comprising a tire of a vehicle.

29. The method of claim 27, the step of faciliting refreezing comprising the step of blowing second air onto the object, the second air having a temperature less than the temperature of the first air.

30. A slider having a surface intended to interface with ice or snow, comprising:

a power supply for generating power;

a heating element configured to convert the power to heat at the surface, the heat being sufficient to melt an interfacial layer of ice at the interface;

a controller for controlling delivery of power to the heating element to control a coefficient of friction between the slider and the ice or snow.

31. The slider of claim 30, wherein the slider takes the form of one of a shoe, a snowboard, a ski, and a snowshoe.

32. The slider of claim 30, the power supply comprising a battery.

33. The slider of claim 30, the slider being in a form of one of a ski, a skate and a snowboard, wherein the controller is responsive to user commands to modulate power applied to the surface such that speed of the slider is controllable.

34. A system for thermally modifying an ice-to-object interface, comprising:

a power supply for generating power;

a heating element coupled to the power supply to convert the power into heat at the interface; and

a controller coupled to the power supply to limit a duration in which power is applied to the heating element such that only an interfacial layer of ice melts at the interface.

35. The system of claim 34, the interfacial layer having a thickness less than about five centimeters.

36. The system of claim 34, the interfacial layer having a thickness between about one micron and one millimeter.

37. The system of claim 34, the power supply configured for generating the power with a magnitude that is substantially inverse proportion to a magnitude of energy which melts the interfacial ice;

the controller configured to limit the duration such that the duration has a substantially inverse proportion to a square of the magnitude of the power.

38. The system of claim 34, further comprising a sensor coupled with the controller for detecting temperature of the interface and for generating a feedback signal representative of the temperature to the controller.

39. The system of claim 34, the power supply comprising at least one of a battery, a capacitor, a flywheel, high-voltage power supply.

40. The system of claim 39, the capacitor comprising at least one of a supercapacitor, electrolytic capacitor, and an ultracapacitor.

41. The system of claim 34, the heating element comprising a thin film of conductive material that transfers the heat from the heating element to the interface to change a coefficient of friction between the object and the ice.

42. The system of claim 34, the heating element comprising a semiconductor material that converts the power into heat at the interface to change a coefficient of friction between the object and the ice.

43. The system of claim 34, further comprising a switch coupled to the controller for receiving a control signal from the controller to limit the duration in which the power is applied to the heating element.

44. The system of claim 34, the power supply, heating element and controller being configued with an object that forms the ice-to-object interface, the object being selected from the group consisting essentially of an aircraft, a windshield, a mirror, a headlight, a power line, a ski lift structure, a rotor structure of a windmill, a rotor structure of a helicopter, a roof, a deck, a building structure, a road, a bridge structure, a freezer structure, an antenna, a railroad structure, a tunnel structure, a cable, a train structure, a ship structure, a drilling platform, an icemaker structure, and a road sign.

45. A method for heating an object to a temperature T, comprising the steps of:

applying power W to the object in a magnitude approximately inversely proportional to the energy sufficient to raise the temperature of the object to temperature T; and

controlling time of the applied power W in a duration inversely proportional to W².

46. A method for cooling an object to a temperature T, comprising the steps of:

removing power W from the object in a magnitude inversely proportional to the energy sufficient to cool the temperature of the object to temperature T; and

controlling time of the power W in a duration inversely proportional to W².

47. A windshield deicer, comprising:

a windshield; and

a substantially transparent heating element disposed with the windshield that generates heat in response to applied power in a magnitude sufficient to melt an interfacial layer of ice on the windshield.

48. The windshield deicer of claim 47, the heating element being selected from visually transparent semiconductor material having an electron gap larger than about 3 eV.

49. The windshield deicer of claim 48, the material comprising one of ZnO, ZnS, and mixtures thereof.

The windshield deicer of claim 47, the heating element being selected from transparent conductor material.

The windshield deicer of claim 50, the material comprising one of indium tin oxide (ITO), tin oxide, thin metal films, and mixtures thereof.

52. The windshield deicer of claim 47, further comprising a protective coating on the heating element.

53. The windshield deicer of claim 47, further comprising a power supply for generating the power.

55. The windshield deicer of claim 47, further comprising a controller for limiting duration of the applied power such that a heat diffusion distance into ice is less than about a thickness of the interfacial layer.

56. The windshield deicer of claim 53, the thickness being between about one micron and one millimeter.

57. The windshield deicer of claim 53, the heating element configured into a plurality of heating elements forming a plurality of segmented regions, the controller configured for applying the power to each of the plurality of heating elements to de-ice segments of the windshield.

54. The windshield deicer of claim 51, the power supply comprising a vehicle battery.

58. A method of modifying friction between an object and ice/snow, comprising the steps of:

applying a first pulse of thermal energy to an interface between the object and the ice/snow, the first pulse being sufficient to melt an interfacial layer of ice/snow adjacent the object; and

refreezing water forming the interfacial layer to form a first bond between the object and the ice/snow.

59. A method of claim 58, further comprising the steps of applying a second pulse of thermal energy, after the step of refreezing, to re-melt at least part of the interfacial layer and refreezing the re-melted interfacial layer to form a second bond between the object and the ice/snow.

60. A method of claim 58, the step of applying comprising pressing a hot cylinder against an object in the form of a car tire.

61. A method of claim 60, further comprising electrically heating the hot cylinder.

62. A method of claim 60, the step of refreezing comprising pressing a cold cylinder against the car tire.

63. A method of claim 58, the step of refreezing comprising utilizing car air conditioning.

64. A method of claim 58, the step of applying comprising applying pulse power to a metal heater in thermal communication with the interface.

65. A method of claim 64, the heater being formed of a material with low heat capacity.

66. A method of claim 64, further comprising the steps of discharging a capacitor to the heater.

67. A method of claim 66, further comprising the step of charging the capacitor with a power supply.

68. A method of claim 67, further comprising utilizing a switch to charge and respectively discharge the capacitor.

69. A method of claim 58, the step of applying comprising coupling a hot plate through one or more holes to a slider base adjacent the ice/snow and part of the object.

70. A method of claim 58, the step of applying comprising applying electrical pulse power to a heater coupled with a base of an object in the form of a ski.

71. A method of claim 70, further comprising activating braking action of the ski by one of a manual switch, a ski motion switch, an accelerometer, a pressure-activated switch, and a motion sensor.

72. A method of claim 58, the step of applying comprising applying pulsed electrical energy to one or more heating elements in the base of an object in the form of a snowboard.

73. A method of claim 58, further comprising utilizing a portable battery as a source of energy for the step of applying a pulse of thermal energy.

74. A method of claim 58, the step of applying comprising utilizing a pulse action lamp to heat the object.

75. A method of claim 74, the object in the form of a rotating tire, light from the lamp temporarily heating respective zones of the tire which melt the layer, rotation of the tire refreezing the layer.

76. A method of claim 58, the step of applying comprising utilizing a metal brush against an object in the form of a car tire.

77. A method of claim 58, the step of applying comprising utilizing a photoflash lamp illuminating through the object to the layer.

78. A method of claim 58, the step of applying comprising utilizing a car exhaust to heat the hot cylinder.

79. A method of claim 58, the step of refreezing comprising utilizing a car air conditioner.

80. A method of claim 58, the step of refreezing comprising utilizing an electric Peltier'"'"'s element.

81. A method of heating an object to a desired temperature, comprising steps of:

storing thermal energy insulated from the object and in a magnitude at least sufficient to heat the object to the desired temperature; and

adjusting one or both of physical and thermal properties of an interface between the thermal energy and the object to transfer at least part of the thermal energy to the object.

82. The method of claim 81, wherein the method further comprises a step of transferring the energy to an interfacial layer of ice to disrupt adhesion of ice to a surface of the object, the desired temperature being zero degrees Celcius or higher.

83. The method of claim 81, wherein the step of transferring comprises disrupting the adhesion of ice to the surface of at least one of an aircraft, an aircraft wing, an automobile windshield, a boat, a road, a bridge, a sidewalk, a freezer, a refrigerator, an icemaker, a ship, a train, a drilling platform, a building, a runway, and a window.

84. The method of claim 81, the step of adjusting comprising transferring the thermal energy from a first surface of a membrane to a second surface of the membrane through deflation of the membrane.

85. The method of claim 81, the step of adjusting comprising periodically pulsing the interface to provide periodic heating of the object.

86. The method of claim 85, wherein the step of periodically pulsing comprises a step of periodically moving components of a heating element to modify a heat transfer rate between a heat storage and the object.

87. The method of claim 86, the components comprising a plurality of grooved insulating elements.

88. The method of claim 87, the step of storing comprising heating one of a liquid and/or gas, the step of adjusting comprising flowing the liquid or gas adjacent to the object such that thermal energy from the liquid or gas transfers to the object, to heat the object.