Fulid ( Discussion )

In your discussion, include: Compare the Actual measured pressure head with the Ideal pressure head calculated using the Bernoulli equation. Discuss any disagreement between the two results.

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Discussion

From the calculation has shown, the actual pressure head is diferent than ideal pressure head this is due to the rictional losses occurred when the water ow through the convergent-divergent duct. There are two types o rictional losses occurred in the duct where the rst riction is called the skin-riction which is due to the roughness in the inner part o the where the uid comes in the contact o the pipe material. The second one is called orm riction which is due to the obstructions present in the line ow and it may be due to a band and control valve or anything which changes the course o motion o the owing uid. Furthermore, the uid is assumed without any eddies o uid swirled in the venture duct however, this will only happen in the ideal condition and ideal apparatus only and in actual case there are rictional losses and eddies o uid swirled in the venture duct and caused the results that we obtained is diferent. astly, the paralla! error is also one o the causes that caused actual cases result diferent with the e!pectation results. This phenomenon occurred when we recorded the reading rom the maniolds . If the ConvergentDivergent duct is inclined upwards, what will be the changes of the distribution of the corresponding total head !, the dynamic "v #$#g% and pressure "p$&g% heads' "iscussion o

# the $onvergent-"ivergent duct is inclined upwards, the corresponding total head %, will stay constant and the pressure head will increase at the upstream due to the diference in height. The ow will continue until the pressure head at upstream e&uals the elevation head at downstream thus velocity head will decrease until 'ero when the uid comes to rest. This is based on the theory o (ernoulli e&uation where the velocity o uid increases when the pressure decreased and vice versa. )oreover, the velocity o the uid will get afected by the cross sectional area. From the graphs has shown it is obvious that the pressure head will decrease rom wide area duct to narrow area duct. This phenomenon is due to the velocity increase when the water reaches the narrow area than decrease again when it pass through the wide area duct. *here the velocity increases when the uid ows through a small cross sectional area and vice versa. Few precautions must be taken in this e!periment. First o all, the readings must be taken careully to prevent paralla! error and our eyes must be parallel with the measurement so that accurate date can be obtained. +ll the bubbles are make sure to be removed when adusting the water ow rate.