How does a jet engine work?

first_imgAirbus IS PREDICTING STRONG Initial reservations Higher bypass engines of the 1960s and 70sIntroduced in the early 1960s, the bypass or turbofan engine not only supplied more power but was more economical. The shroud of cooler air surrounding the hot exhaust stream also muffled engine noise, eliminating the need for complex noise suppression devices.The ratio of cooler fan air to hot jet exhaust is called bypass ratio (BPR). Early turbofan engines had a relatively low BPR of 1.5:1, but wide-body aircraft in the early 1970s like the 747 changed that number significantly to 5:1.This trend has continued through the following decades with the Airbus A330 and Boeing 777 using even higher-bypass ratio engines of up to 100,000 lbs thrust. Bigger, better, fasterThe jet engine has come a long way from its infancy enabling lower fuel consumption, reduced noise and emissions, plus more power, efficiency and reliability today. Those early jet engineers would surely be impressed!Fuel consumption of the jet engine has declined by 49 per cent overall and per passenger by 82 per cent while reliability has soared to where the engine is now the most reliable system on a plane.center_img When jet engines first appeared in service in the early 1940s, aeronautical engineers were skeptical that these cantankerous new powerplants would ever propel a commercial aircraft.They produced little thrust, burned too much fuel, were painfully loud, and often caught fire or shed turbine blades. Those same engineers would be astonished at the power, reliability, fuel efficiency, and low noise and pollution levels of today’s massive turbofan engines. Jet engine basicsThe basic principal of the jet is that air, sucked into the engine at high speed is compressed by rows of small compressor blades, then mixed with fuel in a combustion chamber under extremely high pressure, jettisoned past turbine blades driving the compressor, and then finally exits the exhaust pipe producing forward thrust. Add a large fan at the beginning of this cycle, and you have the basic components of a modern turbine engine.Engineers soon discovered they could harness more power by installing larger turbines at the front or rear of the engine. As much as 5,000 lbs of additional thrust was produced, offering significant performance improvements.last_img read more

South Asia’s tiniest baby survives major surgery

first_imgA baby girl weighing just 520 gm has become the tiniest in South Asia to survive a major abdominal surgery. The girl, born premature at 26 weeks of pregnancy, was operated upon as 12-day-old in Udaipur following progressive distension of her abdomen because of which she was unable to get the milk feed. The surgery entails a very high mortality ranging between 60% and 80% and the chances of survival were less than 10% in the Udaipur case.The baby, Jhanvi, was born in February this year to Umesh and Madanlal Arya, hailing from Madhya Pradesh’s Shivpuri district. She was conceived after 29 years of marriage by in-vitro fertilisation (IVF) technique. Paediatric surgeon Praveen Jhanwar and his team carried out the emergency abdominal surgery under general anaesthesia which lasted one-and-a-half hours. The post-operative course was like a rollercoaster. There were several hurdles, infections and blood transfusions along the way and regular screening of heart and brain was performed to rule out any bleeding in brain.Dr. Janged said Jhanvi’s weight was now close to 2,110 gm and that her progress and clinical course in the neonatal intensive care unit was satisfactory.last_img read more

Djokovic meditates to ‘lose fear and stress’

first_imgTyphoon Kammuri accelerates, gains strength en route to PH NEXT BLOCK ASIA 2.0 introduces GURUS AWARDS to recognize and reward industry influencers LATEST STORIES Djokovic said apart from tennis he has always looked at ways to improve himself, which he terms his “philosophy of life”.“It has always been, not just for tennis, but in general there’s always something that you can improve and get better at as a person and as a player,” he said.“That’s probably the most exciting thing about life, is that every day is a new opportunity for you to get better.”Djokovic faces South Korea’s “NextGen” star Chung Hyeon in Monday’s round of 16. MOST READ Djokovic has become involved in meticulous off-the-court preparation in recent years. He has a strict, gluten-free diet and is an advocate for well-being.The new year has given him the opportunity to analyse aspects of his game and preparation.“When it comes to tennis, I obviously was excited to analyze my game,” he said.“First of all, I wanted to get the right team of people around me, experts in their field, so they can contribute to the process and the journey of working on my body and my game.“Improving different aspects that are there to be worked on. Thankfully there is always something to work on.”ADVERTISEMENT The Serb former world No.1 is playing in his first tournament since Wimbledon in July and he has a brand new support team, headed by eight-time Grand Slam champion Andre Agassi as coach.   Djokovic said after reaching the fourth round of the year’s opening Grand Slam on Saturday that he now meditates on a daily basis.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutout“Yes, I do. I’ll tell you what. I don’t want to tell you what I gain with it, but I’ll tell what I lose with it,” he said.“I lose fear. I lose anxiety. I lose stress. I guess, in the end of the day, that’s what you’re looking for.” Kammuri turning to super typhoon less likely but possible — Pagasa View comments 76ers climb to 6th in East, beat Bucks Trending Articles PLAY LIST 00:50Trending Articles02:44Djokovic wins Laureus Sportsman of Year Award01:57Taiwan bridge collapses, at least 14 injured; rescuers fear six trapped01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City Globe Business launches leading cloud-enabled and hardware-agnostic conferencing platform in PH Don’t miss out on the latest news and information. Slow and steady hope for near-extinct Bangladesh tortoises Novak Djokovic. APNovak Djokovic says meditating has helped him overcome fear and stress that comes with playing elite tennis.The 12-time Grand Slam champion, 30, says he often turned to the practice during his long spell out of the game last year with elbow trouble.ADVERTISEMENT 2 ‘newbie’ drug pushers fall in Lucena sting John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding Read Next Brace for potentially devastating typhoon approaching PH – NDRRMClast_img read more