L'aspetto in assoluto piu affascinante è che avevo scritto ESPLICITAMENTE e senza possibilità di fraintendimento:
CAVITAZIONE e MOTORI TURBOFAN
Ma innanzi all'IGNORANZA piu ABISSALE, si sa: non esistono nè suggerimenti utili, nè posizioni di umiltà.
Dunque vediamo, cosa dicono i manuali, i trattati e le pubblicazioni scientifiche in merito alla CAVITAZIONE nei motori degli aeromobili:
Vediamo cosa dice il maggior produttore/fornitore mondiale di propulsori per uso civile/commerciale: la Rolls Royce:
Forse è bene estrapolarlo ed evidenziarlo:
- "to prevent VAPOUR LOCKING and CAVITATION of the FUEL, and a fuel heater to prevent ICE CRYSTALS forming"
This system may include an L.P.---->pump<----
The low pressure ---->pump<---- of the eingines is usually built in one unit with the high pressure fuel ---->pump<---- of the respective engine.
CAVITAZIONE ---->maggiore<---- rispetto al passato sia a causa dei ---->nuovi motori<----
La CAVITAZIONE, comunque: ritengo essere l'elemento principale. Essa produce il deterioramento delle pale dell'elica che... causa ancora maggiore CAVITAZIONE.
My fuel pump running whit around 12V whith engine not running
• Dramatic loss of flow rate
• “Gauge Bouncing”
• Ratchet or grinding sounds from pump
• Inconsistent or loss of fuel pressure
• Temperatures above 120°F (50C)
As bad as the symptoms of this condition are, the results of this condition are often permanent, even if what caused the condition in the first place was fixed. Loss of fuel delivery pressure will also result in a lean-out condition as well that can result in engine damage.
Typically, even with very short amounts of time of exposure to cavitation (depending on severity) will cause damage to the fuel pump. This damage results in a direct loss of capacity and efficiency. Often as noted when unchecked, this damage to the pump results in operating conditions that quickens cavitation exposure at each use. Eventually, the fuel system resorts to complete failure to build or maintain pressure. For all fuel systems of any manufacturer, this failure can be avoided as it is not a result of a manufacturing defect, but a result of a fuel system design failure.
C.P. No.I128
MINISTRY OF TECHNOLOGY
AERONAUTICAL RESEARCH COUNClL
CURRENT PAPERS
Temperature and Fluid Property
Effects on Cavitation in
Aircraft Fuel Pumps
LONDON: HER MAJESTY’S STATIONERY OFFICE
---->1970<----
PRICE 8s Od [40p] NET
It is very important that jet fuel be free from water contamination.
[omiss]
An industry standard chemical test for the detection of free water in jet fuel uses a water-sensitive filter pad that turns green if the fuel exceeds the specification limit of 30ppm (parts per million) free water
Tuttavia nel caso di soluzioni acquose, approssimando la densità dell'acqua a 1 kg/L, si ha che 1 ppm ≅ 1 mg/L.
Messaggio orinale: https://old.luogocomune.net/site/newbb/viewtopic.php?forum=61&topic_id=2976&post_id=256874