Monday, October 15, 2007

Return of the Thermal Shock

Well, its been quite some time since the incidents I am about to write about here, but I believe that these do deserve a mention.

A query on Answers.com using the search term "Shock" (yes, an internet search, do you really expect this lazy-bum-wired-into-the-www fellow to ever look up a term in a hardback dictionary?) gives various results, and from them I will list the ones that most closely match the context of this post.

Shock1 (shŏk)

1. Something that jars the mind or emotions as if with a violent unexpected blow.
2. The disturbance of function, equilibrium, or mental faculties caused by such a blow; violent agitation.

The most common kind of shock that we always seem to be discussing about is Electric Shock, especially with the "Shock laga laga laga Shock laga" adverts doing the rounds.

However, the thing that I am about to discuss here is, as you must have guessed by the title, to heat. (thermal, thermodynamics, heat - all related things)

Now, keeping in line with the meaning, a thermal shock would be something that causes a blow by means of heat. Lets delve into the relevant details to better understand the situation and its implications.

As a part of my job description, I have to take part in Full Vehicle A/C performance testing. This activity is done on a vehicle chassis dynamo-meter in a closed climate controlled chamber. Now, to do this test, the chamber is kept at a temperature of 45o Celsius, gotta match the actual temperature conditions of the Indian summer after all. And compared to the control room, which has three heavy duty split air conditioners that can bring the room down below 20o, the chamber becomes something of an oven, capable of serving fresh baked psycho. Especially when the test is underway, the vehicle is doing 100kmph on the dynamo-meter and the engine cooling fan is more than keeping up.

So in the month of May, I was taking part in this A/C performance testing activity, and often had to go from the control room to the chamber during the test. From a cold 20o room to a 45o oven with 100kmph air blast had become the thermal shock I took on an hourly basis, sometimes more often.

And as if that was not enough, the same thing returned in September, where for two days I was re-involved in testing, and thus back into the realm of thermal shock. Hence the nomenclature of the post.

However, the best moment of thermal shock did not come in its return. It had come on a particularly hot May Day of testing.

We had to change some engine room components on the vehicle after completing a test cycle, and having run in that heated chamber for two hours, the engine was pretty much boiling. To cool it down quickly we decided to bring down the chamber to 15o and also manually turn on the engine cooling fan of the chamber to create an airflow of 50kmph. And this is the moment when out boss decided to walk in on the chamber from the afternoon heat of that day. Expecting a similar environ inside the chamber, he walked into a Himalayan storm. The look on his face while gesturing to us in the control room to cut out the chamber fan through the observation window will be the signature "thermal shock" image imprinted on our minds. For a long time to come.