Archive for March, 2009

Rear diffusers in formula 1 – in controversy

update – Diffuser hearing result is out. My article “Diffusers legal in F1”

So what exactly is the rear diffuser controversy in formula one? I did some reading and understanding about that and would like to present a basic understanding about it.

  • Aerodynamics has two major functions in a F1 car:
  1. increase downforce of the car i.e. push the car down on the road providing better grip and thus handling
  2. reduce the drag on the car and consequently improving top speed of the car.
  • Diffuser is a component involved in improving the aerodynamics of the car.
  • One way of producing the required downforce on the car (other than front and rear wings) is what I can be simply explained as the ‘converse of the airplane effect’ – The air flow over and below the car is adjusted in such a way that the pressure over the car is higher (air flows at lower velocity, in accordance with Bernoulli’s principle) and the pressure below the car is lower (air flows at higher velocity). Thus, with a higher pressure on top, it pushes the car downward generating the downforce. This downforce can account for as much as 25-30% of total downforce produced.
  • So the principle is to accelerate the air flow beneath the car, to make it it reach larger velocity to get a higher pressure difference. This is done by a narrower flow cross section in the undertray of the car.
  • Then the diffuser comes in. The diffuser as the name suggests is basically a passage with increasing cross sectional area. This slows down the air and increases its pressure. Slowing down the air to a similar speed as that coming from the top helps in preventing flow separation from the undertray profile. Flow separation can lead to heavy drag losses so the diffuser has to be precisely designed for this. The increased pressure also fills up the wake region behind the car and prevents drag losses due to difference in nose pressure and low tail pressure caused due to wake formation.
  • Another way of aiding this process is by opening the exhaust of the car into this diffuser which helps in sucking air more quickly from underneath the car.
  • Now the larger the volume of the diffuser – the better its performance both in terms of reducing flow separation and also through design achieving a higher air velocity at the bottom (i.e. a lower pressure). This is exactly what some of the teams (Brawn, Toyota and Williams) seem to have succeeded in doing.

Firstly it is very important to see and understand a rear diffuser as per rules. As you shall clearly see it does not make any use of the rear crash structure for its aerodynamic passages. Take a look McLaren MP4-24 rear diffuser design – FIA report

There are two aspects to this controversy – the external design and the internal design

  • External – the teams have done is that they have utilized a central section tunnel. This is one point of dispute. However, as per rules a 175mm central section is permissible. Another point of dispute is the extension of the central diffusion section to within 150 mm of extra body work.

(Williams have cleverly employed a secondary or  ‘double decker’ diffuser by modifying the rear crash structure which exceeds the limits.) – for the pic – FIA reports

(Toyota have extended their bodywork to exploit the 150mm rule. This provides an extended diffuser section allowing it work more effectively. There is also a very low level splitter for more smoother air-flow) for the pic – FIA reports

  • Internal – The diffuser in itself consists of many sections. What the above teams have done is that for the central section of the diffuser they have used a incoming hole. And interpreted the rule in such a way that only the diffuser volume is only the central section and not all three sections. This I believe has helped them to have a higher flow rate possible as well as lower pressure. Also the hole coming from the side will help prevent flow separation.

(The internal hole in the Williams diffuser design – FIA reports)

  • All other teams have taken the spirit of the rule and interpreted it simply as all sections must have similar height and width with no entry tunnel. – FIA official report
  • My verdict – If the judging is fair, and only technical stuff considered, this should be allowed. Other teams should play catch up and all the big guns should accept that they have been out-smarted.
  • Another important point was made the other day on commentary – Imagine 10 teams with about 500-700 of the most elite designers and top class automotive engineers in each of the teams’ R&D. That makes about 5000-7000 geniuses pitted against how many FIA rule book officials – 15! Definitely people will find loopholes to exploit!

For more information, clarification, pics – check out my references

Wikipedia – Diffuser

Wikipedia – Ground effects

2009 regulation changes for diffuser: FIA

Excellent pic showing Williams’ Diffuser on car.

Good aerodynamics drawings and parts zoom in view

The actual diffuser on the race car with more clarification@f1fanatic.co.uk

Everything u need to know about F-1 cars ( a seven part awesome series, aerodynamics in part 7) – Click on “taking the lid off F-1 on the website

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Sports update: Cricket and F-1

Sunday was a ideal day for a sports fan like me. The all important fourth day of the India Vs NZ 2nd test in the morning followed by Formula 1 opening race!

First things first- Cricket: India finally drew the test!!! Thanks to a 642 minute enduring century from the surprisingly patient Gambhir! The innings that saved the test and hopefully which would enable us to win the series. Such was the patience that he did not score a single run (while on 83) for almost 12 overs! VVS showed us real class in his boundaries studded century (25 fours in his 125*) and so did Yuvi in his half century (54 off 63, 10 fours). And the patience game was ably supported by the Wall, Dravid (62) and Sachin (64). The partnership between Dravid and Gambhir (133 in 63 overs) is the best defensive batting display I have seen in a very long time. Who would have thought that India could have batted 6+ sessions to save the test match! A commendable feat indeed.

Formula 1: What a dramatic start to the season! It could not have been filled with more twists! Brawn GP scored a 1-2, the only third time in racing history by a debut team. Hamilton coming third after starting last on the grid. Actually Trulli was third but was dropped down later after a penalty for improper rear wing. That meant that the FORCE INDIA cars came in 9th and 11th! And if positions are further cut following the diffuser controversy, FI will get precious points!Ferrari continued their tradition of not scoring any points in the opening race. And feel sad for Vettel and Kubica. Two of the better drivers who should have got points but for their recklessness! And Kubica was not even on KERS!

Aditya writes about qualifying and the actual race in detail. I am thinking of writing more on rear diffusers and KERS soon…

And I am definitely not impressed by the current scoring pattern 😦

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A starry starry night…

starry-night

I had always been interested in astronomy… Reading a lot and also watching a lot of films on discovery and natgeo… And also seen through the telescope a few times. But over the years, like many other interests I could not follow it. And so when the COEP Astronomy club organised a star party – I knew this was one of a kind chance!

There were about 70 students including regular club members. A ‘semi-luxury’ bus and a Sumo had been arranged for transport. We started with some delays at around 19.00 IST (Indian STRETCHABLE Time as someone quipped). With few other ‘traffic’ delays we reached the site by 9.30pm. There was loads of fun on the bus with antakshari! People were coming up with some really long forgotten songs!

The site chosen was a farm considerably far from the outskirts of Pune – it was a very well chosen site. No artificial lights and a very kind and nice-hearted farmer was there to help. And a moonless night has been chosen! Orion was already setting when we reached there – so we quickly settled to watch and hear about it. The constellation was charted and both the Hindu and Greek mythology stories told. It was amazing. Other constellations like the Canis Major (containing Sirius – the dog star) and Canis Minor (the two dogs of Orion the hunter) were also pointed out (with a help of a really brilliant laser, i must appreciate – totally professional). We also saw the messier object in Orion – a star cluster.

A quick dinner – poli-bhaji pulav – n we were ready to go again. And then the real fun. For about 2-3 hours it was just and the sky. Starting with the Great Bear to Pole star and then the Twins – Gemini, Cancer – its brlliant “beehive” heart, the majestic Leo, Saturn(and its rings) in Leo, Virgo, the broken necklace, Bootes, Corvus, Hercules, the gateway to heaven. It was just too awesome!! Complete with stories and all! A quick tea break and we watched the stories of the two Mars rovers – Spirit and Opportunity. And all were introduced to the superb software – Stellarium. Its freeware (!) and the thing for an amateur astronomer. Various constellations were shown using it and discussed. All this on a screen with projector n laptop! Very well organized!

And as we sipped tea – the mighty Scorpio started rising. It was an awesome site to see Scorpio in its full glory! It is beyond words what it feels like. N I being a Scorpio, and it being the best zodiac signs (both to watch in the sky and in reality – Yeah bring it on!) it was a double treat!

As it started getting late – it also started getting very very cold. It was hard to imagine that it was a summer night. An open field and a slight  breeze made matters worse. But I enjoyed the cold – It kept me up!

4 sufficiently large telescopes served the purpose of probing into into the night sky! A cherry on the cake was Jupiter with 5 of its satellites alongwith Saturn and its rings! And dozens of sparkly M-objects and nebulae as well! N yes – half a dozen meteorites were seen too!

It was an amazing experience – no doubts about that. What I felt cannot be described in words. The sheer size of the constellations as they fill up the night sky is trully mind-blowing! And the way the heavens seem to revolve about. Its one thing to take a casual look at the sky and another to observe it over a period of time. The heavens put up such a brilliant show for anyone who cares to watch. I can now understand why the early humans felt that the earth was the centre of the entire universe – the stars make one feel so special – and lucky!

And I can imagine why did the early humans framed the zodiac signs and constellations and weaved the mesmerizing stories about them. Imagine yourself — back in time – and the whole night sky above you – beautiful, mysterious and yet strangely appealing. Who wouldn’t see and wish their own life in the stars? It was the playground for their imagination. Sadly today people chose prime time TV over this marvelous spectacle of nature.

I have decided to attend as many star-parties (as they are fondly called) as I can…

A morning breakfast of delicious poha-buscuit-tea and a return journey full of jokes completed the awesome experience!

1: The beehive cluster in the heart of cancer (M44). YES! These many stars were actually visible in the eyepiece!

2. Scorpio – The red heart – Antares(the yellow star in near centre), the tail curving to the left and the head and pincers to top right; with the milky way in the background

3. Leo (may be a bit hard to imagine) : a lion looking at you with head to the left. the reverse quedtion mark forming the mane of the lion coming down to its feet with body in centre and right angled traingle to left forming the tail!

4. Orion and Sirius:

Orion the hunter with the three stars as his waist and two stars(red and other) above forming his shoulder and two others his legs (similar to above two ones). A fuzzy patch below the central and the other forms the sheath. The bright star to the lower  left is Sirius, the dog star. Experts will locate Canis Major and Minor as well!

orion-and-sirius

5. Messier objects: Spectacular star clusters/galaxies/nebulae which fill up the night sky:

for a table of most of them (actually taken in one night!) http://gregscheckler.wordpress.com/2008/03/11/messier-object-marathon-march-8-9-2008/

6. To end the post – this wonderful pic of the rosetta nebula (not visible to the naked eye of course!)

And people ask me “Why to look at the stars?”!

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[Disclaimer: All images courtesy the internet. To see original images as well as many other pictures click on them. Thanks to all]

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India struggle in 2nd test

Well, 3 days are over and India are already following on. In response to mammoth 619 by NZ, INdia managed just 305. And worse, we lost Sehwag in the second innnigs too! Things looking bad already – its upto the famed batting to come out of the hole they have dug themselves. And Indian bowling again missed the knockout punches after reducing NZ 23-3 in first innings… a trend I am getting familiar with

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INDIA WIN FIRST TEST!!!

In another display of pure awesomeness, the Indian cricket team won the first test. Winning a test after a whopping 33yrs in NZ, team India look all set to win the three match series!

Harbhajan took 6 wickets to restrict NZ to 279 (again! wonder how many times that has happened?!). This left India with 39 to win which was chased down bya blazing Gambhir (30*, 6x4s) and surprisingly Dravid! (was hoping to see Sehwag actually). Tendulkar was man of the match for his 160. He donated the money to the Tiger conservation fund – a real nice gesture one must appreciate. Dhoni gave a classic post match interview in which he stated the importance of team contribution, finding the right length, taking the aggressive decision of bowling first. Overall a clean n professional performance – outclassing NZ in all respects. A well deserved win!

Final scoreboard

The next one in Napier also promises to be a batting delight… hopefully India will win that too…

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Awesome basketball shot!!

This happened at ZEST ’09 at my college. The man was none other than ace COEP player and my friend and classmate Mahesh Hase. I will talk less n let you watch… enjoy 🙂

I have seen people attempt to basket one just before the timer turns to zero… never really seen such a shot yet! – once in a lifetime shot!!!!!! TOTALLY COOL!

Sadly, I could not catch it live…

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Day 2: India still in control!

India ended the second day at 278-4 with Tendulkar and Yuvraj at the crease. A Steady response i would say. India were a bit down on the run rate. But this can be duly appreciated to Vettori’s tactics and a pretty disciplined performance from the bowlers.

The morning started on a horrific note with sehwag (24) run out on a direct hit about 50 yards away. It was a risky run, had it not been a direct hit he would have made it. Some would call it foolish, some aggressive I would chose the term impatient. But thats that. The Indian batting too lacked the flair it usually has with all batsmen – Gambhir (72), Dravid (66), Laxman (30) and Tendulkar (70*) playing steady and dodgy innings. Some chances were gone begging including a dropped catch of Tendulkar. Gambhir had some luck as a 50-50 LBW decision went in his favour when he was on 6. Laxman was a victim of the second new ball. Martin took 2 wickets while O Brien castled Dravid with a brilliant delivery – hit nothing but the top of off-stump. Text book perfect!

But overall, Indian ship seems on course albeit a bit slow. The strategy should be to play out tomorrow entire day and make about 280+ and give NZ the bat on day 4 morning.

Scorecard

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