The pressure in one point of the network is the sum of energies of dynamic and static pressures These transformations of energy are reversible or irreversible. The head loss is irreversible loss of pressure because the pressure drop is converted into heat or noise that you do not know transforming into pressure. (mecaflux pro 3D)
Keywords::
Pressure drop calculations software drop Reynolds Number Head losses Loss Formula load drop Pressure drop regular pressure losses Loss Plan hydraulic load flow calculations aeraulic Loss load losses Colebrook-White formulas losses led Roughness Viscosity
Design fans, ventilation air conditioning, blowers and computers fan
Understand and master the ventilation fans, air conditioning blowers or computers fan design:
Before discussing the technical specifications of the fan air conditioning, ventilation fan, or ventilation,recall the economic and financial stake of correct sizing of ventilating fans . .The market potential for systems with high energy efficiency is (we shall demonstrate) huge yet underexploitedA fan impeller can rotate 24h/24h, its performance can be catastrophic if the operating point is not suitable for flow or pressure network segment that it feeds.Often, as a precaution, the fan is oversized and adjustments are made in the form of valves whose degree of openness generates a loss to regulate the flow..
The optimum ventilation system performance can reach at the level of the propeller, of 0.8, with a suitable propeller to the engine, the flow rate and desired pressure delta. Unfortunately it is rare that the consulting firm, has the propeller design software, and a propeller efficiency of 0.2 is not uncommon. And the ventilation systems equipping our buildings, factories, businesses, administrations .... are all potential sources of energy and income.(the energy saving is considered income because it participates in the profits by reducing operating expenses).Consumers, policy makers and buyers are more educated, informed and competent in terms of energy saving. If before we buy a brand of washing machine without worrying about energy consumption, today we evaluate its quality design primarily due to its energy efficiency!
No need to use the ecological argument (because obviously) to sell a system whose performance been cared:a consulting firm can easily stand out from another, in a call for tenders in advancing the economic argument of profitability in terms of operating cost:
As for the axial liquid pumps, the purpose of the fan is to generate a pressure increase at a given rate. The air systems of air conditioning and ventilation must transfer air through ducts and conduits at a flow rate stipulated in the specifications. This flow rate is determined by the volume of space to be ventilated or air conditioned. The use of mecaflux for example, (Mecaflux is a software for calculating head losses, partner for HELICIEL) allows the technician to determine the pressure drop generated by the movement of air, to the specified flow rate. Role for the fan willto produce an increase in pressure equal to the pressure drop to the flow of the specifications.Performance is a product, and propellers are often the weakest link in this performance. We will remedy this situation and produce value added!
The design method will be that of a propeller with a shroud. The result of pressure is the main objective:
The design method is that of a ducted propeller. The pressure parameter is a major goal, lthe propeller will be heavily loaded, the maximum negative pressure generated by a propeller is located in its area of 0.75 times the radius of the blade tip.The area of the blade root can not achieve high pressure variation due to the apparent low speed.To increase the pressure and prevent leakage, the root radius blade axial pump can be located 50% of the radius of the blade tip. A compromise between speed and achievable pressure must be found.
- This type of fan is suitable for high flow rate but can not achieve a very high delta pressure with a good performance as the area of the blade root will be less effective than the area radius 0.75.Strong delta pressure between the upstream and downstream of the propeller, generated in the most effective area suffer losses at the blade roots.
- This configuration of the propeller fan has the blade root which begins to 0.5 times the radius of the blade tip. The speed at the blade root will be close to that of the blade tip. The effective area covers the whole blade. Delta pressure generated by the fan propeller may be greater. But, because of the narrowing of the passage section, the flow will remain low, otherwise high pressure drop, cause us to lose the benefit of expected pressure.
- PC fans, for generating a high flow rate to cool the CPU, do not need a lot of pressure, however, the helices pc fans are often of the second type. As we have seen for shrouded boat propeller performance is often sacrificed for reasons of space, but also cost. It is amazing to think that the computerwhose cooling is a source of energy, is equipped with PC fan who perform poorly.
This Case is designed to ensure optimum cooling .
A CPU has given optimum performance for a given temperature. Fan noise and consumption of computer are not the only nuisance, of a fan of poor performance, the performance of our CPU will therefore be reduced. The fan on the graphics card is also used to cool the processor graphics card. So the performance of the graphics card will also be reduced if the fan is poorly adapted. A short course on the forums dealing with computer fans and graphics card fans quickly gives the tone: How to reduce the noise of the computer fan is a recurring issue... Warns users know that the performance of their computers are linked to good cooling and they do not hesitate to invest in more efficient computer fans than those originally supplied. A computer propeller fan, is like a propulsion propeller and it will also have a efficiency linked to its size . Good computers fans are therefore large ..!