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  1. 2 points
    It could be that I'm going blind but I didn't see the word 'better' in any part of the question!
  2. 2 points
    I was drawing the diagram of the cycle and I could notice that the flash chamber creates a decreasing both the Entropy and Temperature to send the leaving one-stage vapour, to the high-pressure compressor. With the purpose of increase the COP and decrease the compressor power input.
  3. 2 points
    Lisho Thomas

    Why tyres are made black in color?

    Tyres are mixture of various rubbers with carbon black added. Carbon black improves traction and wear resistance of pure rubber. Another reason is that black color has higher absorption capability by which the tyre of any vehicle becomes adhesive to road
  4. 1 point
    when two objects are comes in contact, and required contact surface area about to 100%, lapping is required, eg. any valve valve seat and sealing device, if the contact area is not about 100% chances of leaking is thre if not properly lapped. in that way lapping is done when sealing is required. where as honing is require when fitments is the case. where sealing is not governing, but relative motion is the case for friction free movements. correct me if any mistakes.
  5. 1 point
    I think it's about their main geometry, Shivank. I mean lapping is plane, honing is cylindrical. But these are old memories (about 1997-98).
  6. 1 point
    The purpose for a governor on at CI engine is the same as the purpose for a governor on any machine: to maintain constant speed under varying load conditions. DrD
  7. 1 point
    Tolerances are allowed so it aid in interchangeability of the product during use, assembly and when subjected to different conditions. It is most derived from the purpose of which the product is to be used for. Environment i.e temperature , application depending on speeds, assembly so it can suit global use.
  8. 1 point

    What is 'CC' of a bike? How does it matter?

    This is one important point missing in the two previous answers. The "cc rating" of an engine is a volume measure, as previously stated, but it is not the actual cylinder volume. Rather, it is the swept volume of the cylinder, also called the "displacement" of the cylinder. The actual cylinder volume is always somewhat greater than this value because the piston at TDC does not leave zero cylinder volume. The small volume remaining at TDC is called the "clearance volume," the volume available for the early stage of combustion. DrD
  9. 1 point
    With "Gear Hobbing", both Cutter and Gear are in action or rotation, With "Gear Shaping" only the Cutter is in action or rotation ,, tool feed remains the same for both !!
  10. 1 point
    Though your question's somewhat vague, intentionally increasing clearance (boring) the cylinders is to increase cylindrical volume, to increase compression ratio and improve power. Unintentionally increased clearance (from wear) will decrease compression ratio due to creating a larger volumetric area which decreases amount of compression per amount of gas allowed in to the cylinder. Also allows for leakage.
  11. 1 point
    Hobbing is the process of roughly, quickly cutting teeth in a gear. A hob is a rotary device which, used for worm, spur or helical gears. Is often used for a known gear type or mass production where cost efficiency is paramount. Shaping is when a power tool (such as a bridge port or boring mill) cuts individual teeth. For an unusual type of gear.
  12. 1 point
    Drill sleeves are often used with drill bits which have tapered shanks. The tapered shank inserts into a sleeve of matching taper in the drill chuck.
  13. 1 point
    Well, to answer this in simple terms.. Rigidity is the maximum resistance an object can offer before it deforms, in other words, it is the minimum force required to deform an object. Torsional Rigidity : The minimum force required to deform an object by twisting through a unit dimension..(in this case, for twisting the dimension is in angle of twist) Lateral Rigidity : Again, the same logic.. The minimum force required to deform an object by bending along the lateral axis through a unit dimension..in this case, the dimension of bending is normally in mm or other length measure scale.. (if the bending load is applied on the longitudinal axis, then the object will not bend, instead the load will act like a compression load), Both Torsional and Lateral Rigidity are considered for the design of shafts with rotating components like gears/pulleys, etc.
  14. 1 point
    It leads to less compression work to second stage of compression, as at first compression temp goes up and pressure develops to get more compressed pressure at output it must intercooled. As pressure increases temp increses so, to avoid higher temp at output it must intercooled
  15. 1 point
    A good question. However, to start off the photo is of a centre lathe and not a Capstan lathe. However, back to the difference... a Capstan lathe has the base of the turret mainly permanently fastened to the bed of the machine and the turret has an independent slide. On a turret lathe Both the turret and the turret base move along the bed of the machine. Turret lathes are generally used for larger work whereas capstans are mainly used for bar work.
  16. 1 point
    Clutch need trust force to engage while Coupling normally use for transfer the torque.
  17. 1 point
    CFD is a computer based flow simulations, where the aim is to solve the Navier-Stokes equations. The equations to be studied are a consequence of the laws of conservation of mass, momentum and energy. FEM is a computer based solid, heat and flow simulations, where the aim is to integrate equations. The equations to be studied are mechanical partial differential equations which are approximated by a set of algebraic equations or a set of ordinary differential equations.
  18. 1 point
    in heat transfer, we study about process of transferring heat from one body to an other body like conduction ,convection & radiation but in thermodynamics we study about the effects of transferring heat on body like internal energy , entropy, enthalpy
  19. 1 point
    thermodynamics is defines the relation between heat and temperature with energy and work in a system. its also a large scale analysis. also its is not counting the heat transfer rate heat transfer determines the heat transfer from a system to the surroundings though the conduction, convection and radiation modes of heat transfer. this is also helps to identify and reduce energy lose through heat energy
  20. 1 point
    The foot valve normally found at the bottom of the submerge pump at the column in the tank
  21. 1 point
    Atanas Sechkov

    Why parabolic fins are preferred ?

    Because they provide a better stream by directing more of the mass that comes in contact with them.
  22. 1 point
    The first step in determining an inventory situation is to use a technique called ABC analysis. It is an inventory control method based upon a statistical principle discovered by a 19th century economist, Vilfredo Pareto. He observed that a small number of situations in a population would often dominate the results achieved. Therefore, controlling the vital few would go a long way to controlling the whole. This observation is known as the “Management Principle of Materiality” and is recognized today as Pareto’s Law. When ABC analysis is applied to an inventory situation, it determines the importance of items and the level of controls placed on the item. By dividing a company’s inventory into different classifications– A, B, C; managers can focus on the items that account for the majority of the inventory. The adaptation of Pareto’s Law of the vital few and trivial many follows a pattern: A inventory accounts for about 20% of the items and 80% of the dollar usageB inventory accounts for about 30% of the items and 15% of the dollar usageC inventory accounts for about 50% of the items and 5% of the dollar usage ‘A’ items have tighter controls on inventory records and more frequent reviews of forecasting, demand requirements, order quantities, safety stocks, and cycle counts.‘B’ items have similar controls to ‘A’ items but reviews are less frequent.‘C’ items have the simplest controls. They are only important if there is a shortage of one of them. Thus, ‘C’ items can be ordered in larger quantities and have higher safety stocks.ABC analysis puts emphasis on “where the value is”. By focusing efforts on higher value inventory, a company can assign proper resources to attain the optimum inventory levels, reducing inventory costs, and ensuring customers’ needs are met.
  23. 1 point
    Due to quenching(sudden change in temperature) during the hardening process,undesired stresses develop in the metal.Tempering is the process to relieve those stresses by heating(usually up to half the melting point) and then cooling it slowly.Tempering is essentially required after hardening.
  24. 1 point
    Arvind Laad: Major difference is the type of flow & the working principle. In a single acting reciprocating pump (recip) the flow is intermittent in semi-sinusoidal form with gaps in between. In a centrifugal pump the flow is continuous. If a Recip is connected to a long pipeline, this can set up surges & resultant vibration & noise due to intermittent flow. Therefore it is necessary to provide surge protection equipment like a surge tank or surge vessel to prevent damage to the pipeline. The pipeline is more prone to what is known as Water Hammer (this subject is too vast to be described here) Another important consideration is that inadvertent closure of valve in the discharge line for a recip can cause severe damage because it is a positive displacement pump due to overpressure. So a pressure relief arrangement is essential. In the centrifugal pump also, a damage can take place, but not due to overpressure. The line does not get over-pressurized like in case of a recip, but the fluid gets churned & gets slowly overheated. The damage therefore is delayed, but due to heating & not by over-pressure.
  25. 1 point

    What is EDM & When do you need it.

    Electrical discharge machining (EDM is a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks). Electrical discharge machining is a machining method primarily used for hard metals or those that would be very difficult to machine with traditional techniques. EDM typically works with materials that are electrically conductive.
  26. 1 point

    Explain the process of Squeeze Casting

    Squeeze casting as liquid-metal forging, is a process by which molten metal solidifies under pressure within closed dies positioned between the plates of a hydraulic press. The applied pressure and instant contact of the molten metal with the die surface produce a rapid heat transfer condition that yields a pore-free fine-grain casting with mechanical properties approaching those of a wrought product. The squeeze casting process is easily automated to produce near-net to net shape high-quality components.
  27. 1 point
    Carburizing is a heat treatment process in which iron or steel absorbs carbon liberated when the metal is heated in the presence of a carbon bearing material, such as charcoal or carbon monoxide, with the intent of making the metal harder. Example - precision gears Nitriding is a heat treating process that diffuses nitrogen into the surface of a metal to create a case hardened surface. These processes are most commonly used on low-carbon, low-alloy steels, however they are also used on medium and high-carbon steels, titanium, aluminum and molybdenum example: crankshafts
  28. 1 point
    Yes, its true that the effective diameter is APPROXIMATELY between the major and mean diameters. And this line intersects the flank in such a way such that the width of the threads and the spaces between the threads during their engagement is same, In this case it makes a PERFECT thread. But there are many errors induced in actual situation like pitch errors, thread angle errors, etc. whereas effective diameter is the dimension that decides the quality of fit between screw and nut. Since engineer A is concerned with strength, he can take into account the "functional diameter" which accounts for the errors induced and is more than the effective diameter. Since engineer B is not concerned with strength, and only intends for providing lubrication which is necessary for maintaining frictions in mating parts especially when dynamically loaded or exposed to vibrations, he/she may consider the effective diameter along with the tolerance grade specified with the pitch/effective diameters, depending on the type of engagement required. Thus an effective diameter acts as a base for deciding the strength and tolerancing of screw threads. I rephrase my posted question, earlier being What is the effective diameter of screw thread? What is its significance in designing of a screw thread?
  29. 1 point
    This still does not really define what the effective diameter is. You figure shows something labeled "effective diameter," but the dimensions do not terminate at any particular feature on the thread. Visually, it looks like you are saying that the effective diameter is the mean of the major and minor diameters, but that is only a rough, imprecise, visual interpretation. How could you argue with someone who said it was slightly more or slightly less than half the difference between the two? Your figure does not identify a feature that ties down the "effective diameter." The use of a modifying adjective like "effective" implies that this diameter is "effective" or perhaps an "average" between two (or more) actual diameters. For this to make sense, it is necessary to specify the way in which "effective" is defined. Let me give you an example. Engineer A is concerned with the strength of a bolt made with this thread. For him, the "effective" diameter is the diameter that defines the area effective in resisting breaking the bold. Engineer B is no concerned at all with the strength of the bold, but rather is concerned with coating the bolt with a lubricant. For Engineer B, the effective diameter is the diameter that defines an equivalent cylinder to be smeared with lubricant. These may, or may not, be the same diameter. "Effective" only makes sense provided the sense in which it is used is defined.
  30. 1 point
    Both hydraulic and pneumatic systems leak, but the consequences of the leak is almost always worse with hydraulics. This is a major factor in favor of pneumatics in places such as crew spaces on shipboard. On the other side of the coin, a major pneumatic leak makes a worse noise than a substantial hydraulic leak, so that is also a consideration.
  31. 1 point
    ABS- it allows the brakes to be applied while maintaining a tractive contact with the road. it does not allow the wheels to be stopped a once. if it was stopped at once due to inertia(because of the speed with which it comes), the vehicles skids. it is more prominent in low friction surfaces like on ice, wet road etc. In ABS the wheels are not stopped at once. It grips the disc mounted on the wheel. the disc is pressed and released with a gap of nanoseconds. thus the driver do not actually feel it. It increases the braking distance. EBD- It is an electronic device that is mounted on the vehicle, that actually varies the amount of braking force on each wheel depending upon the road conditions. if one wheel is on a high friction surface less braking force is required on that wheel. thus by sensing the road conditions the amount of brake force is varied.
  32. 1 point
    The original question was, "Why is first angle method preferred over third angle?" I think in the long run, it all comes down to local custom and tradition. Both convery the same information, so neither it truly superior to the other. That said, there is one basis for a good selection that might tilt in favor of one or the other. It is desireable to minimize the number of hidden lines in a drawing, so if one method results in more hidden lines than the other, the second option is preferable. Again though, I think it is a matter of familiarity, what we are all agreed upon, all of which is known as convention.
  33. 1 point
    Its a valve. It is located in the cooling circuit, between the engine and the radiator. If it opens it allows flow of water, assisted by a water pump, to take place from the block to the radiator in order to allow the block to "give up" excessive heat. It is a self regulating device and it is calibrated to open at a particular temperature - usually about 95 degrees C. It has a hysteresis also, that is a gap between the open and close temperature due to mechanical friction within the device itself and therefore after cooling has taken place it may not close again until the temperature drops to 90 degrees C - a hysteresis of 5 degrees C. So in this example, when the engine gets to temperature, it should maintain an operating temperature of between 90-95 degrees C. Why is this important? It is critical for a couple of reasons, firstly the many machined limits and fits of critical moving parts are designed with the prescribed operating temperature in mind. Secondly, and maybe more critically, the lubricating oil viscosity is too thick at low temps and too thin at higher temps. Oil breaks down rapidly when subject to too high a temp and closely machined mechanical parts experience boundary lubrication - that is metal to metal contact. Probably the best way to screw up your engine is to allow it to overheat! Irlanski
  34. 1 point
    When you say "nomenclature," I presume you are speaking of the specifictions (dimensions, materials). Based on that understanding, I think the answer is, with only that, you cannot evaluate the torque. You need to know a good bit about the combustion process that takes place, and that requires a knowledge of the fuels, the temperatures, and a lot of thermodynamics. If you have a credible P-V diagram for the engine at the operating point of interest, then a dynamic analysis of the engine can provide the output torque, based on that P-V diagram. It is not simple, and it requires quite a lot of calculation, but it can be done with some accuracy. But, and this is a big but, it will only be as good as the P-V data you start with.
  35. 1 point
    Drafting is essentially drawing a picture, whether in 2D or 3D, and providing dimensions and notes. A drafter may do some "catalog engineering," (selecting parts such as bearings, seals, etc. from a catalog), but drafters do not use any truly advanced mathematics (as a rule). Design, on the other hand, may be making a sketch, but it is also providing the analysis to justify the selection of component sizes (based on stress, deflection, fatigue, etc.), determination of system dynamic response and assuring that criteria are met, etc. Design goes much, much further than drafting.
  36. 1 point
    primary objective of inter-cooling is to obtain higher pressure at lower temperature......eventually it reduced amount of work to be done on gases.....which results in higher efficiency
  37. 1 point
    1.ram air cooling 2. intermediate ram air cooling 3. surface cooling 4.boiling 5.engine injection cooling 6. auxiliary injection cooling
  38. 1 point
    significantly large temperature and pressure difference, one vapor compression refrigeration cycles become impractical. One of the solutions for such cases is to perform cooling in two or more stages (i.e., two or more cycles), who work in the series. These refrigeration cycles are called cascade refrigeration cycles
  39. 1 point
    improving the performance of the system is to remove the flash gas at an intermediate pressure.so we are using flash chamber
  40. 1 point
    Akanksha Mahra The jack can be raised and lowered with a metal bar that is inserted into the jack. The operator turns the bar with his hands in a clockwise direction. This turns the screw inside the jack and makes it go up. The screw lifts the small metal cylinder that are above it. As the jack goes up, whatever is placed above it will raise as well. To lower the jack the bar is turned in the opposite direction. https://www.facebook.com/photo.php?fbid=1015237968575 3183&set=a.389510768182.168169.260450433182&type=1
  41. 1 point
    Think of Design for Assembly as prototyping. You make a design that works, that can be built in a shop. Design for manufacturing involves shifting part placements, part types, etc. so as to make sure it can be easily manufactured, repeatably and cheaply, with many part placements done in a simple manufacturing style. Take an engine for example. A prototype (design for assembly) may require machining by machinists, and assembly by the engineers/machinists. Fasteners, connectors, etc wherever it makes sense in the design. But for design for manufacturing, you'd design it such that as many fasteners as possible are on the same side at the same angle, so they can be easily placed all at once by a machine. Something that can't happen if they are all over the place. So you are taking into consideration how the piece will be manufactured on a large scale instead of just how to make the design work.
  42. 1 point
    clutch is a device use to engage or disengage the shaft of the gearbox to the shaft of wheel, while coupling is used to joint two shaft permanantely or temporary,...
  43. 1 point
    Design for assembly: The whole design is done on the basis of how the assembly of all the parts will take place. Its different from design of manufacture, because DOM the basic criteria is how the manufacturing process will be done on parts. which machine available, which can be easy to manufacture in the workshop with the tools and machines available,....
  44. 1 point
    Dial Gauge is a measuring instrument used to measure small distances Slip Gauge is a piece of hardened steel which is machined in a standard size.This is used to accurately make gaps
  45. 1 point
    generally tolerence are required for to control the quality of the product during mfg. GD & T is coontroll the dimension of the product during manufacturing .it mean it give the perticuler range of geometric parameters like surface finish,flatness,strigtness,...etc..., sometime tolerence are given for the purpose of the type of fit requirement between two meting parts, sometime tolerence stack up analysis is also required when more than 2 parts are assembled to each other..
  46. 1 point
    When we manufacture any product, usually we manufacture it by casting or forging process. To get a proper surface finish of that product we need a proper machining. At the time of maching a certain amount of material usually removed from the surface of the core product. For this reason a tolerance is needed over the designed dimension to maintain the actual dimension. Beside this reason, tolerances also kept to maintain the needed dimension after thermal expansion or contraction at the time of solidification during casting process.
  47. 1 point

    For what Fanning diagram is used for?

    Arvind Laad Head Engineering at Creative Ashtech Power Projects Private Limited This diagram is used to find the nature of flow of viscous slurry- whether it is laminar or turbulent. It is also used to derive the coefficient of friction in such cases in order to work out the pressure drop in these pipelines & thus fix the slurry pump parameters.
  48. 1 point
    thermal diffusivity can be defined as a material-specific property for characterizing an unsteady heat conduction.mathematically,it is thermal conductivity divided by volumetric heat capacity; with the S.I unit of m^2/s Thermal diffusivity signifies the rate of heat transfer into the solid. If it is higher then less time is required for the heat to penetrate into the solid.its significance is also seen for fire protection.
  49. 1 point
    In normal helical gears there is no problem of impact stresses but there are axial thrusts on the bearings of shafts on which they are mounted.these gears are good for moderate power transmission because bearing can be designed.But in very high power transmission design of bearing for a small and compact system becomes very tough and unemployable.Thus herringbone gears were designed to eliminate these axial thrusts.This gear contains both right hand helical profile and left hand helical profile on same gear as you can see in diag. .The axial components of transmission force is cancelled by each other on same gear.Thus eliminating the problem of thrust force. these gears are used in racing cars where high power transmission is required and bearing size can not be increased after certain limit.
  50. 1 point
    major differences are PELTON WHEEL- high working head, tangential water flow, low specific speed, low discharge and impulse type of turbine KAPLAN TURBINE- low working head, axial water flow, high specific speed, very high discharge and reaction type of turbine