otto cycle efficiency

When the efficiency of diesel cycle approaches the Otto cycle efficiency?

Two condition arises for the above question- At same compression ratio- ,At same compression ratio diesel cycle efficiency is less than otto cycle.The diesel cycle efficiency depends upon the cut-off ratio. So when the cut-off ratio is equal to 1 then it approaches to otto cycle efficiency as then V3/V2 =1 so V3=V2 which ultimately ensures that the heat addition is done at constant volume and approaches to the otto cycle at the same compression ratio. At different compression ratio- ,As the above condition can only be satisfied when there is same compression ratio so if compression ratio is different then diesel cycle have more efficiency than otto cycle so since the compression ratio of diesel cycle is always more than otto cycle so one cannot interfere in that although the diesel cycle efficiency also depends upon the cut-off ratio which increases with increased output and thereby reduces the cycle efficiency since the efficiency of diesel cycle varies inversely with the cut-off ratio. So as the throttle is given in a diesel engine it approaches to the otto engine efficiency when the compression ratio’s are different. THANKYOU. Hope this helps.

Why is the diesel cycle efficiency higher than the Otto cycle?

In otto cycle air-fuel mixture is taken as working fluid,where as in diesel cycle only air is taken(fuel is injected in combustion stroke). Naturally, Self ignition temp of working fluid, in diesel cycle is more. So we can increase the ,compression ratio, in diesel cycle. So the Efficiency of ,diesel cycle, is more than that of ,otto cycle,. But if we consider both cycles run normally with ,same compression ratio, the efficiency of ,otto cycle ,is more than that of ,diesel cycle.

Which is more efficient at same compression ratio, the diesel or Otto cycle? Why?

As per bookish knowledge is concerned, Well, at both constant heat addition and heat rejection the ,Otto cycle ,will give more thermal efficiency than diesel cycle as the area under the P-V diagram to heat supplied ratio is ,greator ,for Otto cycle. But, if you look this thing practically and let’s say that C.R is 16 for instance, then the petrol engine will not even work as there will be huge detonation in it, but diesel engine will run fine and its efficiency will be larger. At let’s say for C.R 6 the petrol engine will run fine, but diesel engine will not even start as the auto-ignition is not reached. So, this efficiency of Otto( Petrol engine) being greator than Diesel works for only when C.R is below 10- 12, other than that practically diesel cycle has greator efficiency.

Which cycle has the greater thermal efficiency an Otto cycle or a Diesel cycle?

Otto cycle has more efficiency than diesel cycle. Let us keep the compression ratio fixed for both the cycle which is, ( V2/V1),. Area enclosed by the both the cycle in the P-V diagram represents the work done per cycle for respective cycles. So, the ,area(1–2–3–5–1) > area(1–2–4–5–1),, i.e., work done per cycle by ,Otto, cycle is greater than ,Diesel ,cycle. Now, Thermal Efficiency=(Workdone/Heat Input) So, the thermal efficiency of, Otto, cycle is more than ,Diesel, cycle.

Under which condition the efficiency of brayton cycle and otto cycle are going to be equal?

When the compression ratio of Otto cycle is equal to pressure ratio of brayton cycle ,the efficiency will equal, bcz efficiency of Otto cycle is the function of compression ratio and efficiency of brayton cycle is the function of pressure ratio. Don't forget to upvote,,,,,!!!!

Why is the thermal efficiency of ICE less than that of an ideal otto cycle?

This is because an ideal Otto Cycle neglects key elements of real internal combustion engine technologies that have been implemented. the ideal Otto Cycle neglects all mechanical friction. This includes piston friction, crankshaft friction, any place you have moving parts, there is friction and it is ignored the ideal Otto Cycle neglects any power draw from mechanisms that the real internal combustion engine needs to function properly. There is no belt, no crankshaft, not even an allowance for the camshaft. the ideal Otto Cycle neglects heat losses to the engine block. The only heat loss included is the heat rejection of the hot exhaust gases during the exhaust stroke the ideal Otto Cycle neglects the fact that fuel is not be fully combusted by the time the exhaust stroke begins. the ideal Otto Cycle neglects any performance adjustments necessary from an environmental standpoint. A typical set of parameters for a real internal combustion engine results in a minimisation of carbon monoxide, unburnt fuel, and oxydes of nitrogen; the set of parameters to minimise all of these is often working against one another, so it's a compromise position which is not the optimal one from an engine efficiency standpoint. These differences point to the fact that there is a wide chasm between an idealised cycle and a real-world working cycle.

What is the thermal efficiency of an Otto cycle which compression ratio is 1:14?

What is the diesel vs. Otto cycle based on efficiency?

Both diesel and petrol engines use the Otto cycle (intake, compression, combustion, exhaust) unless the engines are two stroke and you can get both diesel and petrol two stroke engines. The only difference is that a petrol engine uses a spark to ignite the combustion part whereas the diesel relies on the act of compression to ignite its fuel. in a diesel the compression part of the cycle ends in combustion whereas in the petrol engine the compression phase is FOLLOWED by the combustion stage. In both cases there is compression then combustion. Most model aeroplane engines are basically two stroke diesel