PRIUS skrev:
Men det gäller att göra det på rätt sätt annars får man som på en del äldre bilar problem med att det bildas en luftkudde i motorrumet och då strömmade ingen luft genom kylaren och man fick problem med att kylarvattnet kokade.
Först tänkte också att motorkyllningen sklle bli mindre med skivan under motorn, men så länge det inte är helt tät verkar det kunna öka luftflödet genom kylaren i stället för tvärtom när bilen rullar, se
http://omgpham.com/aerodynamics-of-engi ... ing-part-1Citat:
After air passes through the radiator, what happens to it all? Well some of it quickly exits through the under-body, but not much because air flow under a car is slow from all the drag caused by the gearbox, exhaust, suspension, etc... The rest of it stays inside the engine bay and creates a lot of turbulence as it collides with the engine and other components. This is therefore the limiting factor as it creates a high pressure, slow moving air (turbulent), so now the difference between pressures in front and behind the radiator is dramatically reduced. Air flow across the radiator decreases as a result...
http://omgpham.com/aerodynamics-of-engi ... ing-part-2 Citat:
Temperatures were measure at two different spots, first was at the intake air filter which has cold air ducted to it. The other was just in front of the engine.
Below are temperatures recorded before/after the under-body panel was installed. Ambient air temperature was 22°C, and all measurements were taken within a two hour period.
Interpretation of collected data...With the under-body panel in place, temperature readings dropped slightly. But the real improvements aren't seen in the temperature drops but rather the increased air flow. I have no way to quantitatively measure air flow, but I noted the operation of the thermo-fans. When travelling above 60km/h, the thermo-fans didn't cycle on/off as much. To me, this is a clear indication that more air is flowing through radiator/engine bay and therefore keeps the engine temperatures more stable at speed.
Before installing the under-body panel, travelling at 80-100km/h, the thermo-fans turned on every 4-5mins for a period of 30-45 seconds depending on the engine load. With the under-body panel installed, travelling at the same constant speed, the thermo-fans never turn on until you come to a stop.
Bara när bilen står stilla gör plåten att motorn blir lite varmare, kanske bra på vintern för den kylls nog långsammare med motorn avstängd kan jag tänka mig.
På ecomodders site såg jag att folk förbättrar strömlinjen under bilen och samtidigt stryper luftflödet genom kylaren för att förbättra luftmotståndet, det kan nog vara bra på vintern.