System Mechanics



Disassembling the Nautilus 500 reveals Corsair may have used a radiator identical to that found in their original Hydrocool, as seen in these Tweakup.DK Hydrocool photos (scroll down). This is by no means a criticism since this radiator performs on par with many of today?s 120mm single radiator separates. Inside Nautilus the radiator is located on the base above a grill allowing ambient air to be drawn in via a fan mounted directly above. Corsair chose a fan from Vette Corp specifically the 120x25mm model A1225L12D which runs at 1800RPM producing 74.4CFM. While not as powerful as I might like the unit is certainly quiet and does do the job. Insoafr as the radiator the design follows today's higher end models which eschew atypical tubes in place of flat ellipses which force more water molecules along its interior surface. Two radiators pictured below exemplify the shape of the water "tubes" used in radiators, on the left the Alphacool NexXxos Pro II on the right the Thermochill PA 160.



Corsair's choice of radiator and those pictured above share many similarities as well as differences. An entire article can be written on radiator design when you consider the number of variables alone such as pressure and flow rates across pumps feeding the radiator, metal type, wall thickness. What seems to work well are the elliptically shaped "tubes" which can be seen in the close-up below. When I thought of a radiator I thought of rounded tubes snaking through a series of thin cooling fins, where the tubes would have to "exchange" thermal energy via the fins. From the macro below the ratio of fins versus "tubes" seems to be juxtaposed in a much more efficient design. Where the majority of surface area was once cooling fins it's now water filled "ellipses" or foils these are very narrow in width yet relatively tall. This begs the question how will laminar flow be affected and how will this ultimately affect heat dissipation?



If you have any water cooling experience, more then likely you've come across the term Laminar Flow while reading a review or in the forums. You can always tell when "flow rate" is being discussed because the thread is usually 10+ pages in length and includes multiple heated arguments, as found here at OCForums. To put it simply Laminar Flow describes how a viscous fluid "behaves" as it flows through a tube or over a surface. For our purposes as a stream of H20 flows through a length of tube with a fixed radius the stream divides into layers or Lamina which flow at varying speeds beginning at a rate of 0 at the surface progressively increasing in speed until the center layer, where maximum flow-rate is achieved. Water molecules in contact with the surface area of the tube "adhere" to it based on a set of criteria one being surface friction. Laminar flow is explained below.



Laminar Flow plays a critical role in thermodynamic processes where H20 is used as a transfer medium in PC-cooling. Tube diameter, length, fluid viscosity, H20's specific heat capacity and of course thermal conductivity of the radiator material will all play an integral role in the cooling process. For example a small increase in tube radius will have a powerful impact on flow as explained by Pouiseuilles Law, seen below.



Back to less technical matter's, Corsair has done an excellent job organizing an entire water cooling system into a small container. From the front view the radiator consumes most space while the reservoir and an inverted LAING Thermotech pump consumes the remainder. Electronics have been kept simple, DC-power enters where the wires are split to power the pump and twin speed fan which has its switch mounted on the rear panel. While a temp display or water level indicator would have been nice their absence reduces the price and simplifies installation.



Rotating the unit 180-degrees provides a better understanding of water-flow direction. Heated water returning from the CPU water-block enters through the Quick Disconnect nozzle on the right where it feeds into the reservoir. Although difficult to see from this angle at the bottom of the reservoir an outlet feeds the inlet of the LAING Delphi DDC mounted top-side up. The Delphi or DDC as it's more commonly known then feeds the radiator inlet.



Taking a closer look at the LAING DDC pump we see Corsair organized the system so this pump had to mounted upside down. While this doesn?t seem to affect flow, I did immediately wonder how it might affect the pump long-term? I'm sure Corsair doesn't intend to RMA thousands of units over something as silly as improperly mounting the pump, so I wrote LAING.



Below we see the Delphi DDC model number and serial number. Laing Thermotech is one of the few companies to print so much pertinent information on their pumps, and given their wide use across the industry this is a smart move. This took a little "peeling" back of the sticky pads used to mount the pump although it is snug no worries.



To exemplify how Corsair's choice of flow direction through the cooling systems I've inserted color-coded arrows onto the photo below. The red arrows indicate water returning from the water block which is heated from the CPU, or more accurately carrying the kinetic energy from the processor conducted to it through the water block. Blue arrows indicate water which has transferred that energy (heat) dissipating it through the radiator. This returns to the processor in a continual cycle.



Beyond the specialization of the radiator itself, I was happy to see Corsair organize the cooling cycle such that the water leaving Nautilus and entering the CPU water block has just been passed through the radiator and will be at it's lowest temperature in the loop.