Abstract:
An engine includes a duct containing a flow of cool air and a pump system having an impeller with an inlet for receiving air from the duct and an outlet for discharging air into a discharge manifold. The discharge manifold containing at least one heat exchanger which forms part of a thermal management system.

Description:
BACKGROUND 
       [0001]    The present disclosure relates to a pump system for use with a gas turbine engine to provide a more compact thermal management system. 
         [0002]    Gas turbine engines typically use a number of air-to-air heat exchangers as part of a thermal management system (TMS) to reject internal heat to the engine&#39;s surroundings. Heat exchanger effectiveness depends on area and delta-Pressure across the exchanger unit. As fan pressure ratio has dropped with newer engine designs, heat exchangers can grow prohibitively large in size. Heat exchangers are more difficult to install, heavier, and more costly to produce as size increases. 
       SUMMARY 
       [0003]    In accordance with the present disclosure, there is provided an engine which broadly comprises a duct containing a flow of cool air, a pump system comprising an impeller having an inlet for receiving air from the duct and an outlet for discharging air into a discharge manifold, and the discharge manifold containing at least one heat exchanger which forms part of a thermal management system. 
         [0004]    Further in accordance with the present disclosure, there is provided a pump system for thermal management system, which pump system broadly comprises an air intake for receiving air from a supply of air, an impeller having an intake for receiving the air and an outlet for discharging the air, and a discharge manifold having at least one heat exchanger incorporated therein which forms part of the thermal management system. 
         [0005]    Other details of the pump system for TMS AOC reduction are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a side view of an engine; 
           [0007]      FIG. 2  is a rear view of the engine of  FIG. 1 ; 
           [0008]      FIG. 3  is a side view of an engine having the pump system of the present disclosure; 
           [0009]      FIG. 4  is a sectional view taken along lines  4 - 4  of  FIG. 3 ; and 
           [0010]      FIG. 5  illustrates a side view of an engine having the pump system of  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    In accordance with the present disclosure, a pump is used to raise pressure of flow through a TMS heat exchanger (or set of heat exchangers in series), increasing effectiveness and thereby reducing the required heat exchanger size. The impeller may be driven by the engine towershaft, and thus may be located in the relatively cooler forward region of the engine cowl. Heat exchangers may be closely located to the impeller discharge in a duct which exhausts into the fan duct. It is also desirable to closely locate a Fuel-Oil Cooler (FOC) unit, typically used in similar engine configurations and usually plumbed to the fuel control/pump and the AOC&#39;s. The axial gearbox lends itself well to this design due to the near proximity of lube and fuel system components with the gearbox towershaft. 
         [0012]    Referring now to  FIGS. 1 and 2 , there is shown an engine with a thermal management system (TMS). As can be seen from  FIGS. 1 and 2 , the engine  10  has air-oil coolers  12  and a fuel oil cooler  14  mounted to the engine core  16 . 
         [0013]    Referring now to  FIG. 3 , there is shown an engine  100  having a pump system  102  for the thermal management system. The engine  100  includes a fan  104 , a high pressure compressor  106 , and a turbine section  108 . The high pressure compressor  106  and the turbine section  108  are connected by at least one spool  110 . As can be seen from  FIG. 3 , the high pressure compressor  106  and the turbine section  108  are housed in a core  112 . Further, the fan  104  is surrounded by a cowl  114 . A by-pass flow duct  116  is created between the cowl  114  and the core  112 . Air flow created by the fan  104  passes through the by-pass flow duct  116 . 
         [0014]    The pump system  102  includes an impeller  130  and an intake manifold  132  for delivering air from the by-pass flow duct  116  to the intake  133  of the impeller  130 . The pump system  102  further includes a heat exchanger discharge manifold  134  connected to an outlet  135  of the impeller  130 . Mounted within the heat exchanger discharge manifold  134  is one or more heat exchangers  137  which may be used as air-oil coolers. The manifold  134  delivers air to the heat exchangers  137  and then discharges the air through the outlet  150  into the by-pass duct  116 . If desired, a 360 degree scroll collector  139  may surround the impeller  130 . 
         [0015]    The impeller  130  may be driven via a towershaft  140 . The towershaft  140  may be connected to one of the spools  110 , either a high-spool which connects the high pressure compressor to a high pressure turbine section or a low-spool which connects the fan  104  to a low pressure turbine section or in some circumstances a mid-spool that connects the mid-pressure compressor to a mid-pressure turbine section. The towershaft  140  may be connected to the spool  110  via a drive gear  142 . 
         [0016]    As can be seen from the foregoing description, cool air from the fan stream is taken into the pump system via the intake manifold  132 . The discharge from the impeller  130  flows into a single duct (manifold  134 ) to the heat exchangers  137 . 
         [0017]    As shown in  FIG. 4 , the pump system  102  can be located at any convenient tangential location. 
         [0018]    If desired, the towershaft  140  may be incorporated with an engine accessory gearbox (AGB) using the existing towershaft as a means of the drive power. If desired, the pump system may be incorporated into the AGB housing itself, the towershaft housing, or the layshaft housing to reduce packaging space. 
         [0019]    Referring now to  FIG. 5 , there is shown one embodiment of an engine having the pump system  102  according to the present disclosure. 
         [0020]    By using the pump system of the present invention, it is possible to reduce the size of the air-oil coolers (AOCs) by more than 80% due to the LP rise across the pump. It is further possible to closely integrate the TMS heat exchanger system. Overall TMS system weight will decrease due to the smaller heat exchanger size. Externals packaging may improve also due to reduced AOC size. 
         [0021]    There has been provided by the instant disclosure a pump system for a TMS AOC reduction. While the pump system has been described in the context of specific embodiments thereof, other unforeseen alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations as fall within the broad scope of the appended claims.