Abstract:
A heat extraction system is provided for a laptop computer that comprises a system unit that includes a set of heat sources and a video display unit that is movably attached to the system unit. The laptop computer has air inlets and air outlets that allow air to flow into the system unit, over the heat sources forming heated air, and exhaust the heated air. The laptop computer has a set of tubes, which have an inlet and an outlet, located behind a video display in the video display unit and an air connection from the air outlets to each inlet in the tubes. The set of tubes are formed such that heated air passing through a constriction in the set of tubes changes in velocity and pressure in order to satisfy the conservation of flow rate. Thus, heat produced by the heat sources is extracted from the laptop computer.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to computer system heat extraction. More specifically, the present invention is related to an apparatus for extracting heat from a laptop computer using Venturi Bernoulli heat extraction. 
   2. Description of the Related Art 
   A laptop or notebook computer system has many components that produce large amounts of heat during operation, including, but not limited to the central processing unit (CPU), chipset, graphics card, and hard drives. This heat must be dissipated in order to keep these components within their safe operating temperatures, and both manufacturing methods and additional parts are used to keep the heat at a safe level. 
   The heat sink itself performs two entirely separate functions, both of which are necessary to a central processing unit&#39;s ongoing good health. First, the heat sink acts as a large thermal mass which absorbs heat and stabilizes the central processing unit&#39;s temperature. The heat sink aspect does not reduce or increase the central processing unit. The heat sink simply stops the central processing unit&#39;s temperature from changing too quickly. Secondly, the heat sink acts as a heat dissipater. The heat sink is designed to have a large total surface area and to conduct heat well, so the whole surface of the heat sink gets hot. The weakness of this entire arrangement is the poor transfer of heat from the heat sink to the air, thus, the large surface area of the heat sink attempts to compensates for the poor heat transfer. 
   Currently, to increase the transfer of heat from the heat sink to the air, fans are added to the laptop or notebook computer to speed up the exchange of air heated by the computer parts for cooler ambient air. However, cooling computer components that produce large amounts of heat during operation is an ongoing issue especially within a laptop or notebook computer. 
   SUMMARY OF THE INVENTION 
   The illustrative embodiments provide a laptop computer that comprises a system unit, which includes a set of heat sources and a video display unit that is movably attached to the system unit. The illustrative embodiments provide a set of air inlets and a set of air outlets on the system unit. The set of air inlets allows air to flow into the system unit, over the heat sources within the system unit to form heated air, and the set of air outlets allows the heated air to flow out of the system unit. The illustrative embodiments provide a set of tubes located behind a video display within the video display unit. Each tube in the set of tubes has an inlet and an outlet in the video display unit. The illustrative embodiments provide an air connection that connects the set of air outlets to each inlet in the set of tubes. The set of tubes have a form such that heated air passing through a constriction in the set of tubes changes in velocity and pressure in order to satisfy conservation of flow rate. The heated air produced by the set of heat sources is extracted from the laptop computer through each outlet in the set of tubes. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  depicts a pictorial representation of a data processing system in which the illustrative embodiments may be implemented; 
       FIG. 2  shows a block diagram of a data processing system in which the illustrative embodiments may be implemented; 
       FIG. 3  depicts a chimney-like heat extractor using the Venturi effect in accordance with an illustrative embodiment; 
       FIG. 4  depicts a side view of a laptop computer using a Venturi Bernoulli heat extraction system in accordance with an illustrative embodiment; and 
       FIG. 5  depicts a three-dimensional view of a laptop computer using a Venturi Bernoulli heat extraction system in accordance with an illustrative embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The illustrative embodiments provide for extracting heat from a laptop computer using Venturi Bernoulli heat extraction. A laptop computer may also be known as a notebook computer or a mobile computer. With reference now to the figures, and in particular with reference to  FIG. 1 , a pictorial representation of a data processing system in which illustrative embodiments may be implemented is depicted. Mobile computer  100  is depicted which includes system unit  102 , video display terminal  104 , keyboard  106 , storage devices  108 , which may include floppy drives and other types of permanent and removable storage media, and pointer device  110 . Additional input devices may be included with mobile computer  100 , such as, for example, a mouse, joystick, touch screen, trackball, microphone, and the like. Mobile computer  100  may be implemented using any suitable computer, such as an IBM Thinkpad computer, which is a product of International Business Machines Corporation, located in Armonk, N.Y. Mobile computer  100  also preferably includes a graphical user interface (GUI) that may be implemented by means of systems software residing in computer readable media in operation within mobile computer  100 . 
   With reference now to  FIG. 2 , a block diagram of a data processing system is shown in which the illustrative embodiments may be implemented. Data processing system  200  is an example of a mobile computer, such as mobile computer  100  in  FIG. 1 , in which code or instructions implementing the processes for different embodiments may be located. In the depicted example, data processing system  200  employs a hub architecture including a north bridge and memory controller hub (MCH)  208  and a south bridge and input/output (I/O) controller hub (ICH)  210 . Processor  202 , main memory  204 , and graphics processor  218  are connected to MCH  208 . Graphics processor  218  may be connected to the MCH through an accelerated graphics port (AGP), for example. 
   In the depicted example, local area network (LAN) adapter  212 , audio adapter  216 , keyboard and mouse adapter  220 , modem  222 , read only memory (ROM)  224 , hard disk drive (HDD)  226 , CD-ROM drive  230 , universal serial bus (USB) ports and other communications ports  232 , and PCI/PCIe devices  234  may be connected to input/output (I/O) controller hub  210 . PCI/PCIe devices may include, for example, Ethernet adapters, add-in cards, PC cards for notebook computers, etc. PCI uses a cardbus controller, while PCIe does not. ROM  224  may be, for example, a flash binary input/output system (BIOS). Hard disk drive  226  and CD-ROM drive  230  may use, for example, an integrated drive electronics (IDE) or serial advanced technology attachment (SATA) interface. A super I/O (SIO) device  236  may be connected to input/output (I/O) controller hub  210 . 
   Docking interface  240  may also be connected to input/output (I/O) controller hub  210 . Data processing system  200  may be a mobile computing device, such as a laptop computer or handheld computer. Docking interface  240  provides port replication to allow the data processing system to easily connect to a keyboard, pointing device, monitor, printer, speakers, etc. The docking interface allows the mobile computing device to operate as a desktop computer with the more immobile peripheral devices. 
   An operating system runs on processor  202  and is used to coordinate and provide control of various components within data processing system  200  in  FIG. 2 . The operating system may be a commercially available operating system, such as Windows® XP, which is available from Microsoft Corporation. Instructions for the operating system, the object-oriented programming system, and applications or programs are located on storage devices, such as hard disk drive  226  and may be loaded into main memory  204  for execution by processor  202 . 
   Those of ordinary skill in the art will appreciate that the hardware in  FIG. 2  may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash memory, equivalent nonvolatile memory, or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in  FIG. 2 . Also, the processes of the depicted embodiments may be applied to a multiprocessor data processing system. 
   For example, data processing system  200  may be a personal digital assistant (PDA), which is configured with flash memory to provide non-volatile memory for storing operating system files and/or user-generated data. The depicted example in  FIG. 2  and above-described examples are not meant to imply architectural limitations. 
   The illustrative embodiments use the Bernoulli principle to provide a chimney-like heat extractor with venturis extending up the back of the LCD screen. Using Venturi Bernoulli heat extraction may augment or replace the fan drawing air over the heat sink that sits on top of the central processing unit. 
     FIG. 3  depicts a chimney-like heat extractor using the Venturi effect in accordance with an illustrative embodiment. The Venturi effect is a special case of Bernoulli&#39;s principle, in the case of air  302  flowing through tube  304  with constriction  306  in tube  304 . Air  302  must speed up in constriction  306 , reducing air&#39;s  306  pressure and producing a partial vacuum via the Bernoulli effect. The illustrative embodiments may use a set of tubes which may be one or more tubes. 
   Air  302  passing through constriction  306  is subject to changes in velocity and pressure in order to satisfy the conservation of mass-flux or flow rate. The reduction in pressure in constriction  306  can be understood by conservation of energy: air  302  gains kinetic energy as it enters constriction  306 , and that energy is supplied by a pressure gradient force from behind. The pressure gradient reduces the pressure in constriction  306  in reaction to the acceleration. Likewise, as air  302  leaves constriction  306 , air  302  is slowed by a pressure gradient force that raises the pressure back to the ambient level. 
   The limiting case of the Venturi effect is choked flow in which constriction  306  in tube  304  limits the total flow rate through tube  304  because the pressure cannot drop below zero in constriction  306 . As an example of dimensions for tube  304 , the outer ends may be  1  centimeter while the constricted portion of tube  304  may be  0 . 25  centimeters, although any dimension may be used as long as the tube fits adequately behind the video display terminal of the laptop computer and provides air flow. Tube  304  may be manufactured out of a number of different materials, such as high temperature rubber, a material similar to the housing of the display, or aluminum, which may provide strength as well as additional heat dissipation. 
     FIG. 4  depicts a side view of a laptop computer using a Venturi Bernoulli heat extraction system in accordance with an illustrative embodiment. Laptop computer  400  may be a laptop, notebook, or mobile computer, such as mobile computer  100  of  FIG. 1 . Laptop computer  400  is comprised of system unit  402  and video display terminal  404 . System unit  402  comprises central processing unit (CPU)  406  and fan  408  used to draw air over a heat sink that sits on top of central processing unit  406  as well as other internal components of system unit  402  forming heated air. While the illustrative embodiments use fan  408 , one or more fans may be used to comprise a set of fans. While the illustrative embodiments show one of central processing unit  406 , system unit  402  may contain one or more central processing units. The illustrative embodiments provide a Venturi Bernoulli heat extraction system that is comprised of chimney  410  and hinge duct  412 . Chimney  410  may be one or more chimneys or tubes using the Venturi effect as described in  FIG. 3  and are located behind video display terminal  404 . 
   System unit  402  may comprise a set of air inlets that may be one or more air inlets  414  where air  416  is drawn in over the internal components inside of system unit  402  to cool the internal components. Fan  408  may draw air  416  over the internal components of system unit  402 , such as central processing unit  406  and exhaust air  416  through air outlet  418 . The illustrative embodiments use a set of air outlets that may be one or more air outlets. The illustrative embodiments draw air  416  through hinge duct  412  and then through chimney  410 . While the illustrative embodiments show hinge duct  412  that provides a connection from air outlet  418  to chimney  410 , any type of connection may be used, such as an expandable/collapsible tube as long as the connection is able to conduct air from air outlet  418  to chimney  410  such that a pressure gradient is present. 
   Air  416  passing through constriction  420  is subject to changes in velocity and pressure in order to satisfy the conservation of mass-flux or flow rate. The reduction in pressure in constriction  420  can be understood by conservation of energy: air  416  gains kinetic energy as it enters constriction  420 , and that energy is supplied by a pressure gradient force from behind. The pressure gradient reduces the pressure in constriction  420  in reaction to the acceleration. Likewise, as air  416  leaves constriction  420 , air  416  is slowed by a pressure gradient force that raises the pressure back to the ambient level. 
     FIG. 5  depicts a three-dimensional view of a laptop computer using a Venturi Bernoulli heat extraction system in accordance with an illustrative embodiment. Laptop computer  500  may be a laptop, notebook, or mobile computer, such as mobile computer  100  of  FIG. 1 . As with laptop computer  400  of  FIG. 4 , laptop computer  500  is comprised of system unit  502  and video display terminal  504 . System unit  502  comprises central processing unit (CPU)  506  and fan  508  used to draw air over a heat sink that sits on top of central processing unit  506  as well as other internal components of system unit  502  forming heated air. While the illustrative embodiments use fan  508 , one or more fans may be used to comprise a set of fans. While the illustrative embodiments show one of central processing unit  506 , system unit  502  may contain one or more central processing units. The illustrative embodiments provide a Venturi Bernoulli heat extraction system that is comprised of chimney  510  and hinge duct  512 . Chimney  510  may be one or more chimneys or tubes using the Venturi effect as described in  FIG. 3  and are located behind video display terminal  504 . 
   System unit  502  may comprise one or more air inlets  514  where air  516  is drawn in over the internal components inside of system unit  502  to cool the internal components. Fan  508  may draw air  516  over the internal components of system unit  502 , such as central processing unit  506  and exhaust air  516  through air outlet  518 . The illustrative embodiments draw air  516  through hinge duct  512  and then through chimney  510 . While the illustrative embodiments show hinge duct  512  that provides a connection from air outlet  518  to chimney  510 , any type of connection may be used, such as an expandable/collapsible tube as long as the connection is able to conduct air from air outlet  518  to chimney  510  such that a pressure gradient is present. 
   Air  516  passing through constriction  520  is subject to changes in velocity and pressure in order to satisfy the conservation of mass-flux or flow rate. The reduction in pressure in constriction  520  can be understood by conservation of energy: air  516  gains kinetic energy as it enters constriction  520 , and that energy is supplied by a pressure gradient force from behind. The pressure gradient reduces the pressure in constriction  520  in reaction to the acceleration. Likewise, as air  516  leaves constriction  520 , air  516  is slowed by a pressure gradient force that raises the pressure back to the ambient level. 
   Thus, the illustrative embodiments provide a Venturi Bernoulli heat extraction system that uses a chimney-like heat extractor with venturis extending up the back of the LCD screen. Using Venturi Bernoulli heat extraction may augment or replace the fan drawing air over the heat sink that sits on top of the central processing unit. 
   The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.