Engines Definition and 291 Threads

Homework Statement Suppose that two heat engines are connected in a series, such that the heat exhaust of the first engine is used as the heat input of the second (attached diagram below). The efficiencies of the engines are e1 and e2, respectively. Show that the net efficiency of the...

i was reading on the moller skycar which has multiple wankel rotary engines powering ducted fans for lift, i was wondering if anyone had any information on how many pound of lift one of these engines on a regular ducted fan would have

Well I have always been interested in engines and how to make them more efficient and make more power. Particularly the popular modifying of Ford and GM engines (302ci, 351ci, 350ci, etc.). I am looking for a book that could help me understand how a cam actually works, and what to tweak...

Is it just me, or is it really hard to get good results when you google something lately? It used to be that I would find what I wanted fast, now I search something and I get nothing but garbage. Anyone else notice this change lately?

Hi ! I remember an experiment in school where two volumes of Hydrogen and one of Oxygen were mixed in a test tube set upside down on (at the time !) a platter full of mercury. A spark in two electrodes on top of the tube would trigger an IMPLOSION and the mercury would jump upward to fill the...

Have ceramics come of age for use in ic engines? from what i can make out they do not improve performance by much, but do make the engine more reliable, coating the piston crown and cylinder head seem to be the favorite use, or components that require little or no lubrication..

Why would a velocity stack improve an ic engines performance?

My book states: "To prove that no real heat engine operating between two reservoirs is more efficient than a carnot engine between the same reservoirs, imagine a more efficient engine to drive a less efficient carnot refrigerator. For the combination of the engine and refrigerator you get a...

hey all, I just completed putting a small 2 stroke on my old bicycle, yes majorly geared down, I am actually rather pleased with it. I used an internally geared 3 speed hub on the rear wheel so i could shift back down to 1st gear after being in 3rd and coasting to a stop (you don't have to have...

Could someone explain to me how heat engines and refrigerators and air conditioners work. I'm very confused about the process and if they are isothermic, isovolumetric, or adiabatic. ~Kitty

i found this on another messageboard and couldn't find an answer. any help? Question about jet engines... From: Bisected8 | Posted: 2/6/2006 9:26:42 AM | Message Detail | #001 Is the fuel used to move the fans by way of an internal combustion engine (thus compressing the air and forcing it...

Hey guys ,can u just let me know about the most advanced or developed IC engine.Plz help.

how do you calculate piston speed with a single cylinder engine no transmission what I am trying to do is determine the influence of rod length in that problem

I have a couple of questions about 2 cycle engines: 1) Can someone further explain “time-area” to me in regard to the 2 cycle engine porting? I do grasp the basic concept of time-area values and I do have a formula to calculate the time-area values for a 2 cycle engine however there is still...

Ok, so I feel really stupid asking this question, but I guess you've got to start somewhere to reach somewhere, so here goes nothing: I have this report to write and the title of the report has got me a bit confused. The professor's asked me to "write and present a technical report abut high...

Hi Guys Could Some One Tell Why V-engines Are Better Than In Line Engines

I was reading an article and they were talken about this new hydrogen hummer that will be powered by hydrogen. But it was a hydrogen combustion engine instead of a hydrogen electric vehicle. How does the combustion engine work? I thought hydrogen doesn't have that really quick explosive...

I don't quite understand how it is supposed to work. How do you determine what the flame holder is supposed to look like ,where to put the holes, and how big the holes should be? What are the physics and equations for it?

Does anyone know if there have been any posts on the vegetable oil to diesel conversions. I am very interested in the topic, but couldn't find anything yet. I guess if there is nothing yet posted, this could be the new post. I'll try and get some of the info that I have and post it.

Hello, If anybody could answer this question for me that would be great. I have been wondering about it all morning. In the Diesel cycle for heat engines, on the second stage of operation, the Volume increases while pressure stays the same. I understand how this can be accomplished by raising...

Hello, If anybody could answer this question for me that would be great. I have been wondering about it all morning. In the Diesel cycle for heat engines, on the second stage of operation, the Volume increases while pressure stays the same. I understand how this can be accomplished by raising...

I read this little article today, regarding self-building drug delivery systems. It reads a lot like how our immune system works. Then again, my degree in molecular biology is something for my next lifetime. This is from Scientific American...

Could anyone suggest a book on heat engines at undergraduate level?

As a future engineer, my proffessors teach us to be concerned about pollutant emissions. I always hear about NOx production inside heat engines and turbomachinery. But little is explained about the true nature of this problem. Usually, we are told that NOx is produced at high temperatures...

thinking of a project and was wondering can a jet engine be modified to run on just hydrogen and oxygen as the fuel, or is it too explosive? if not can a pulse jet?

In class, we're being introduced to thermodynamics, and one of the topics is heat engines. Steam engines were also mentioned. Carot engines also entered the pic. They are described as ideal systems. Exactly why are Carnot engines not "real" engines, or are not possible? I'm sorry if...

NERVA2 RE: Watters and Enigma In light of the latest shutdown thread - Nerva - "what the hell" Firstly neither of you have ever posted any replies on that thread. Secondly, i doubt it that you Enigma, are an aerospace engineer. I have been looking at your posts and am amazed at what...

[Note: hi everyone, this is my first post, my name is U235 or more conversly Dion. I am 16] Why is it everytime i look over schematics for the next nuclear rocket engine the design's are completley blindsided to nuclear physics and the harnessing of direct fusion and fission reactions...

Unlike commercial airplane, many fighter aircrafts have the jet engines buried inside the fuselage instead of in pods hung beneath the wings. Do you know why?

A 20% efficient real engine is used to speed up a train from rest to 5 m/s. It is known that an ideal (Carnot) engine using the same cold and hot reservoirs would accelerate the same train from rest to a speed of 6.5 m/s using the same amount of fuel. The engines use air at 300 K as a cold...

I am just about to start my Aero. Eng. degree in a few days time and am currently ploughing my way through all the reccommended reading. A lot of it either gives textual explanations (rather than mathematical proofs or both) or gives a brief description, glossing over anything that may be...

I'm trying to fully understand scramjet engines but I can't seem to find a good source of information. I know the gist of what a scramjet engine is; I want to really understand the physics behind how it works and how the air flows thru the structure. If anyone help me and or knows a site or book...

I am going to inaugurate the "What is happening here?" post series. I am interested on knowing what is happening physically in some aspects of flow around aircrafts. And surely, due to the high level of the co-forum-ers people :thumbs_up , you could provide me an answer, if you want of course...

I am a part of a student organization that will be atempting to design, machine, and test fire an Annulare Aerospike engine. We are now in the info gathering phase and finding it difficult to locate informative and helpful information on the design part. If anyone has any ideas, please either...

FordVehicles.com There have been lengthy delays on Ford's first hybrid car (The Escape). There was news about Ford offering a Focus Hybrid to the public, but with an engine like that, is it neccesary? Honda and Toyota have a strong hold on Hybrid technology as far as compact sedans go...

When a jet aircraft is flying at high speed doesn't the air impacting on the front of the engines compress the air before it gets into the compressor. And how fast does the combusted fuel leave an engine compared to the speed of airflow at the intake?

A number of deceptively simple, but hopefully interesting questions. 1. Why are jet engines so noisy? 2. Is there a way to make them quieter, or otherwise register less on the human ear?

When I was viewing some photos about rocket engines (spatial ones), I wondered me in what mode is operating the nozzle in the normal working.I am going to try to explain it better (do not show me a strange face yet). I studied the different exhaust modes of a convergent-divergent nozzle...

Can someone explain to me how Heat engines work?

Hello, I'm interested in knowing which is the rocket engine of all that have been constructed to date that has major thrust The first in my list is the RD-170, that was used in the Energia launch vehicle, and is still used in the Zenith rocket. The RD-170 rocket engine has a nominal thrust of...

One of the pleasant side-effects of the unpleasant fact that the US pulled out of the nuclear non-proliferation treaties is that NASA is now free to restart research into nuclear thermal rockets. For those not familiar with the concept, a lightweight gas (helium or hydrogen) gets passed...