Engines Definition and 291 Threads

Now, everyone knows that motorcycle engines work at much higher rpms than car engines. They also produce lesser torque than a car, because (and correct if I'm wrong) bikes don't have as much load on them as cars do. Can anybody tell me what goes in an engine that decides that when power is...

If my rocket has two rocket engines going off each at an impulse at 20.00 N/S... If my rocket has two rocket engines going off each at an impulse at 20.00 N/S, then would the total amount of impulse my rocket has be 40.00 N/S? Please answer seriosuly only this is extremely important and...

How are these crafts engines protected from ingress of debris?

Homework Statement An aircraft engine akes in 9000 Joules of heat and discards 6400 J each cycles a) What is the mechanical work output of the engine during one cycle? b) What is the thermal efficiency of the engine? Homework Equations e=W/Qh The Attempt at a Solution A) Qh =...

what is it that stops various toroidal engines, like the rotoblock engine, trochilic engine, myt engine or the engine from being successfull? sealing/efficiency/lubrication problems? or they can't find a strong enough material to withstand the pressure? and is there any credibility to the claims...

Hello, I am building a device that tests the maximum thrust of hobby rocket engines, and I need to know if there is any way to get "streaming time." Time that is recorded at certain intervals. Can someone give me a link? Thanks! ~Nick

I was wondering if anyone would be able to help with this question; Two carnot engines operate in series between a source 800K and a sink of 290K. The first engine rejects 400kJ to the second engine. If both engines have the same efficiency, calculate; (i) the temperature for the source of...

So like it says. It may be a silly question, but I am doing some reading on jet engines (on Wiki) and I am having trouble finding an explanation as to why we want to increase the pressure of the air before it goes into combustion. Does this just another way of increasing the thrust? Thanks...

i need to learn c/c++ to add effect on 3d objects and to use agia physix engine (like adding gravity , refraction,...etc) and i don't know where to start and what to read and what to learn there is so much books and so much programs and lectures (i don't mean the 101 books i mean after that)...

Homework Statement I am not necessarily having a problem with a particular homework problem. It is more of a conceptual issue. I have been reading about Carnot engines and refrigerators. In trying to understand the topic better, I did a little more digging and looked up how a refrigerator...

could anyone tell me how the charge air is used to cool the engine in a charge air-cooled engine?(i mean apart from the charge coming in and cooling, is there a mechanism for cooling the charge before intake)

Hi all, I'm hoping that someone may be able to help! I'm doing a project which has involved me looking at the use of superalloys in Gas Turbine engines (i.e. Rolls Royce, GE etc). As part of that I am looking in particular at the use of Chromium within these engines, does anybody have any...

I don't know a lot about jet engines and how they exactly work but is it possible to run a jet engine without gasoline? Are there any different fuels that can be used for the engine to give more propulsion or give it more time in the air?

Correct me if I'm wrong, but the hottest combustion temperatures will result when the air/fuel ratio is ideal, or stoichiometric, no? I ask, because there seems to be this mentality that a lean mixture will result in even hotter temperatures, and could cause engine damage. This has not...

I was just wondering how these amazing engineering feats support the loads on their wings? Specifically the larger passenger aeroplanes.. such as the 737 and 747. The wings must undergo an extreme number of forces of great magnitude.. how do they not snap off? How the they support their own...

Might a road to significantly faster search engines (25% faster) be via use of a cache of say the 100,000 most frequent search words and phrases utilized, typical for over a year? Might one have perhaps a number of distributive caches for a multitude of different processors and associated memories?

I am having trouble with this question...It is from "applied thermodynamics for engineering technologists" by Eastop (Q5.2 if anyone has it)... The Question: Two reversible heat engines operate in series between a source at 527°C and a sink at 17°C. If the engines have equal efficiencies and...

I'm having trouble trying to get my head around the role entropy plays in a heat engine. When the energy from a hot reservoir enters the engine, it brings a certain amount of entropy with it. Then, the "waste heat" (which is energy) gets rid of the entropy. But, why does it take less energy to...

1. The amount of heat that an engine rejects to the cold reservoir is 3 times the amount of work that it does. What is the efficiency of the engine? e = W/ Qh = 1 - Qc/Qh For this problem, I said e= w/3w. Thus e would equal 1/3 = 0.333. This however is not correct. What did I do wrong...

Hey guys, Just trying to understand this piece of information I have been given. It is for a compression ignition engine. I can see where they get the 115.954 kmol/kmol fuel and 120.204 kmol/kmol fuel from but don't understand how to change the units 0.7027 kmol/kg fuel and 0.7285 kmol/kg...

I have a question on Why the Carnot cycle is not used with real engines? I need to refer to real cycles in my explanation.

[SOLVED] Heat Engines and the Carnot Cycle Homework Statement The operating temperatures for a Carnot engine are Tc and Th= Tc + 55K. The efficiency of the engine is 15%. How do i find Tc?

What do people think of the developments and future of Waste Exhaust Heat Recovery? Thermoelectric Conversion of exhaust heat into electric power to drive auxiliaries. Thermodynamic Conversion of waste exhaust ( + radiator + Charge air cooler + EGR cooler) heat into additional...

O.k i understand that a jet engine gains its thrust by pushing heated air out its nozzel, but i was wondering if that the reason it goes forward is because the speed of it being released out the rear nozzel is moving faster than the air can get pushed out of the way so the some of the force is...

Anyone with any idea about the basic internal design & engines in an electric car?

http://news.uk.msn.com/Article.aspx?cp-documentid=7279188 Surly both engines do not share a single control system.

Homework Statement A 3250 km aircraft takes 12.5 minutes to achieve its cruising altitude of 10 km and cruising speed of 850 km/h. If the plane's engines deliver, on the average, 1500 hp of power during this time, what is the efficiency of the engines? Homework Equations Efficiency =...

If you were a car manufacturer, which of the following cars would you choose to manufacture, supposing you are only allowed to manufacture either kind: 1) a car with a small engine but with a turbocharger; or 2) a car with a big engine Assume that both cars have other variables constant...

Entropy and Engines Homework Statement A heat engine has the following diagram associated with it. There is a heat source which supplies 1000 J of heat energy during one cycle and remains at a constant temperature of 400 K. A heat sink exhausts 700 J of heat during a cycle at a constant...

Source: CBS MarketWatch Interesting developments! Certainly - if this works - it will dramatically reduce fuel consumption. "1,500 fewer airfoils" seems awfully large. But then I haven't counted the blades in current turbine design. I curious as to what the typical blade number is per...

ok now my practicals are 15 days away and i n my friends constantly discuss about advantages and disadvantages of several combinations like 2-stroke SI engine with supercharging or 4stroke CI with CRDi etc etc. since people here are more experienced and have far more facilities than i do, i want...

Homework Statement A traveler in space is moving left and right on y = x^2. He shuts off the engines and continues on the tangent line until he reaches point (4, 15). At what point on the curve should he shut off the engines to reach that point? The Attempt at a Solution Ok, the...

Hi guys, i am doing some calculations on the valve spring of a 4 stroke, 4 cylinder motor vehicle engine. To my understanding, valve bounce will occur once the valve spring is operated at a speed over their natural frequency (which i calculated to be 5500 rev/min). If i were to push the...

i see that pf is the very first results while searching for a physics forum. why?? is it because it has more vistors than other sites? what's google ranking or other search engines base on?

Homework Statement The position of a spaceship is: r(t)=(3+t)i +(2+ln(t))j+(7-\frac{4}{t^2+1})k and the coordinated of the space station are (6,4,9). The captian wants the spaceship to coast into the the space station. When should the engines be turned off? Homework Equations r(t)=(3+t)i...

hi to all, this is my first post here n quite a stupid one:shy::shy: last day i had a discussion with my friend over this.. what exactly is the reason behind that sound of the engine? i mean is it the sound of the explosion of the charge or is the sound of the expanding gases comin out to the...

I have in mind to recreate a Brit v twin (in a fashion) using two single cylinder engines coupled together, as i see it i have three options for the linking method, chain, toothed belt, or gears, gears would be the most (ridged) coupling, the chain and belt would have some flex, the other...

I have a feeling someone is going to be like "Duhhh" on this one. But I got to thinking. I recall reading somewhere that the guy that came up with the rocket engine for use in space got an F on his paper because "I think" the professor said that there would be nothing to push back on the...

Homework Statement A person is a certain distance away from a plane with three equally noisy engines at 120 dB. What is the sound intensity if two of the engines are shut off? Homework Equations B (in dB) = log I/Io The Attempt at a Solution using this equation: 120 dB = 10 log...

Hi I was wondering which of the following titles I should buy with regards to building a fairly simple physics engine for a game idea I have. I don't want to rush in I want to spend my money wisely. The titles are (roughly) as follows: Real Time Collision Detection Game Physics Game Physics...

Homework Statement There are two Carnot engines in series, so that the heat exhaust from the first engine drives the second. Find the overall efficiency of the arrangement which contains only the efficiences of the individual engines. Homework Equations \epsilon = \frac{W}{Q_{input}}...

If you look at any car that has 2 available engines, the big engine's gas mileage sucks compared to the small engine. Just as an example, a 2.4L honda accord uses 9.7L of fuel to go 100km while the 3.0L model needs 11.5L of fuel to go that same distance. Since EPA fuel estimates are done...

So I want to look for specific characters within my .html and .txt files offline. But even when I google offline search engine, I can't find a suitable search engine. Windows Vista Search doesn't seem to have a search engine that works for strings within particular files (it just seems to work...

Hi everyone, We have an argument about gasoline combustion engine and diesel engine. Some say, the diesel engine is stronger than gasoline one. My idea is if the two engines are the same dimension, they must have the same power. Am I right or wrong. Thanks

The inside of an ideal refrigerator is at a temperature , while the heating coils on the back of the refrigerator are at a temperature . Owing to a malfunctioning switch, the light bulb within the refrigerator remains on when the the door is closed. The power of the light bulb is ; assume that...

Homework Statement Under many conditions, the rate at which heat enters as air conditioned building on a hot summer day is proportional to the difference in the temperature between the inside and outside, Th-Tc. (If the heat enters entirley by conduction,this statement will certainly be...

we are learning about heat engines and the 2nd law of thermodynamics...and i don't know how to relate torque to these concepts... the question is... a multicylinder gasoline engine in an airplane, operating at 2500rev/min, takes in energy at 7.89E3 J and exhausts 4.58E3 J for each revolution...

First let me say hello and give an introduction. I have limited academic experiecnce in Physics receiving a C-grade GCSE at 16. I then spent over a decade owning a maintaining a number of motorbikes, cars, and light and medium commercial vehicles and some light plant machinery. Mainly for...

Dear All, I'm still only on my second book of learning C++ although I've had plenty of programming experience writing snippets for games before. The first book was about 350 pages and introduced to me to everything up to and including OOP and inheritance. Now I'm reading one targetted at...

hi. i am looking for a satisfying source about the topic written in the title. it is my semester project. if you can help me i woud be appreciated. thanks already now.