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The programme explores the modelling of dynamic systems by looking at the critical angular velocity of a fairground centrifugal ride and the forces experienced by a gudgeon pin in an internal comb...ustion engine.
Metadata describing this Open University video programme
Module code and title: T232, Engineering mechanics: solids
Item code: T232; 04
First transmission date: 01-06-1980
Published: 1980
Rights Statement:
Restrictions on use:
Duration: 00:24:00
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Producer: Tony Jolly
Contributors: Tony Bright; Dudley Thompson
Publisher: BBC Open University
Keyword(s): Centrifugal ride; Internal combustion engine; Mechanics laws; Newton's laws
Footage description: Shots of a four stroke internal combustion engine. Animated diagrams over the engine show the piston/crank mechanism in motion. Dudley Thompson introduces the programme. Thompson, with the aid of a model of a four stroke piston engine, explains how the engine works. Thompson then goes on to explain why he chose to analyse the forces acting on the gudgeon pin when the piston is at top dead centre. Film shots of a fairground showing a centrifugal ride. Shots of a model of the ride in the studio. Tony Bright explains that he will calculate a safe rotation speed for the ride and test his calculations on the working model. Tony Bright goes on to look at the basic law of mechanics which will be used for both problems in this programme, Newton's Second Law. Animated diagrams illustrate points made. Tony Bright points out the series of steps which have to be worked through in order to use Newton's Second Law in the analysis of the piston engine and fairground ride problems. The steps are outlined on a large graphics board. Dudley Thompson goes through step 1 of the proceedure, assembling the information needed, for analysing the forces acting on the gudgeon pin of the piston engine. He writes on a graphics board as he talks. Tony Bright writes, on a graphics board, the data he has assembled for analysing the forces acting on the fairground ride. Also shots of the model fairground ride in action. Dudley Thompson goes on to step 2 of the proceedure, drawing a free body diagram for the piston/crank mechanism. Tony Bright points out, from a free body diagram of his fairground ride, the forces acting on a man inside the ride. Dudley Thompson moves on to step 3 of the proceedure, applying Newton's Second Law in the form of R = MA. He then goes through steps 4 and 5, deciding on the kinematic constraints which give the form of the acceleration, and elaborating the forces which were identified in the free body diagram. Thompson examines the relative magnitudes of the two accelerations, one due to the weight of the mechanism and the other due to the actual kinematics of the piston/crank mechanism. Tony Bright goes through the remaining steps in the analysis procedure for the fairground ride. He calculates the rate of revolutions for the ride which is necessary in order to keep a man from falling out. Finally, to test the validity of his calculations Tony Bright runs his working model of the fairground ride at the speed calculated.
Master spool number: HOU3372
Production number: FOUT064R
Videofinder number: 1964
Available to public: no