使用實驗方法研究受聲波激擾之後傾噴流火焰受橫風衝擊時的火焰與熱化學特性。透過揚聲器激擾噴流火焰，使用一維熱線風速儀量測噴流振動特性。分別使用高速攝影機及數位相機擷取瞬間與時間平均的火焰圖像。藉由R-type熱電偶偵測火焰溫度。使用氣體分析儀量測火焰的燃燒生成物濃度。未受聲波激擾之噴流火焰呈現雙峰溫度分佈，表現出非預混火焰的特性。在一個由下沉引起的大迴流氣泡區域中，發生貧燃燒和富燃燒。後傾噴流火焰在橫流中受到聲波激動時，呈現三種特徵火焰模態：橫流主導、過渡和噴流主導模態。這些特徵火焰模態，存在於不同的振盪強度和噴流後傾角的情況。 在噴流主導火焰模態，泡芙狀火焰出現了頻率等於聲波激動頻率。當振盪強度超過不穩定性的限制時，由於強大的拉伸效應，使得廻流火焰近乎消失，此特性可作為火焰點火器的應用。火焰熄滅發生在燃燒器管端的背風面區域。溫度和氣體濃度測量結果顯示，在橫流主導火焰模態，燃燒性能在低傾斜角時有顯著的改善；即使在小的振盪強度下，燃燒性能改善也頗為顯著。為了增強噴流火焰在大傾斜角時的燃燒性能， 噴流脈動強度必須足夠大，方能推動火焰呈現噴流主導火焰模態。

The flame and thermochemical characteristics of backward-inclined acoustically excited jet flame in crossflow were experimentally studied. Jet flames were excited by sound waves emitted from a loudspeaker. Jet pulsation characteristics were measured using a customized one-component hotwire anemometer. The instantaneous and time-averaged flame images were acquired using a high-speed camera and a still camera, respectively. The flame temperatures and combustion product concentrations were measured using a homemade fine-wire R-type thermocouple and a commercial gas analyser, respectively. The natural (non-excited) flame presented dual-peak temperature distributions and exhibited features of non-premixed flame. Poor and rich combustions occurred in a downwash-induced large recirculation bubble region. Three characteristic flame modes (crossflow-dominated flame, transitional flame, and jet-dominated flame) were found when the backward-inclined jet flame in crossflow was subject to acoustic excitation. These characteristic flame modes could be observed in different regimes of pulsation intensity and jet backward inclination angle. Discrete flame puffs with a frequency equalling to the acoustic excitation frequency appeared in the jet-dominated flame. The periodic flame puffing became unstable when the pulsation intensity was increased to values near the instability limit. When the pulsation intensity was beyond the instability limit, a strong stretching effect caused the recirculation flame, which played the role of a flame ignitor, to almost vanish. The flame extinguishment then occurred from the area around the lee side of the burner tube tip. The measurement results of the temperature and combustion product concentrations showed that the acoustic excitation, even at a low pulsation intensity in the regime of crossflow-dominated flame, could significantly increase the combustion performance at a low jet backward inclination angle. To enhance the combustion performance at a large jet backward inclination angle, the pulsation intensity must be large enough to push the flame to present the jet-dominated flame mode.

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