CALCULATION OF TEMPERATURE OF VENTILATION AIR WITH VARYING AIR TEMPERATURE AT THE ENTRANCE.

IN THE PRESENT PAPER THE EFFECT OF VARIATION OF THE AIR TEMPERATURE AT THE ENTRANCE ON THE AIR TEMPERATURE ALONG THE ROADWAY IS THEORETICALLY ANALYZED. A GENERAL EXPRESSION IS FIRST OBTAINED FOR THE TEMPERATURE ALONG THE ROADWAY WHEN THE AIR TEMPERATURE AT THE ENTRANCE CHANGES ARBITRARILY. THEN NUMERICAL VALUES OF THAT EQUATION ARE CALCULATED FOR TWO PRACTICAL CASES: SINUSOIDAL AND SUDDEN CHANGES OF THE TEMPERATURE AT THE ENTRANCE. RESULTS OF THE DISCUSSION ARE AS FOLLOWS; (A) IN THE CASE OF THE SINUSOIDAL CHANGE THE TEMPERATURE OF VENTILATION AIR SHOWS A TRANSIENT STATE AT THE BEGINNING OF VENTILATION, BUT THEN REACHES SOME SINUSOIDAL STATE OF VARIATION WITH THE AMPLITUDE REDUCED AND THE PHASE DELAYED AS THE DISTANCE FROM THE ENTRANCE INCREASES. (B) THE EFFECT OF A SUDDEN AIR TEMPERATURE CHANGE AT THE ENTRANCE IS INSTANTANEOUSON THE TEMPERATURE OF VENTILATION AIR AT A SHORT DISTANCE FROM THE ENTRANCE AND IS GRADUAL AS THE DISTANCE INCREASES. TWO PRACTICAL APPROXIMATE EQUATIONS FOR THIS CASE ARE PROPOSED. IN JAPANESE WITH ENGLISH ABSTRACT.