流體力學(xué)知識重點(diǎn)資料(全)(編輯修改稿)
2025-02-04 09:22 本頁面
【文章內(nèi)容簡介】 ，母線稱為馬赫線，圓錐的半錐角稱為馬赫角； 超聲速流場的基本特征： 在超聲速流場中微弱的擾動波的傳播是有界的； 水頭損失的的構(gòu)成： 1. 沿程損失，是沿等截面管流動時管壁切應(yīng)力引起的摩擦損失； 2. 局部損失，是由 的重新分布； 2. 流體元相互碰撞和增加摩擦； ； 4，流動分離形成漩渦等原因引起的損失。 加速度公式的物理意義 ： B點(diǎn)加速度 =B點(diǎn)速度隨時間的變化率（ B的當(dāng)?shù)刈兓剩?+B因空間位置的差異而引起的變化率（ B點(diǎn)的沿各個軸方向的遷移變化率） NS方程的物理意義： 質(zhì)量加速度（慣性力） =體積力 +壓差力（壓強(qiáng)梯度） +粘性力（粘性切應(yīng)力的散度） 伯努力方程的物理 意義： 速度水頭 +位置水頭 +壓強(qiáng)水頭 =總水頭 位置水頭 +壓強(qiáng)水頭 =測壓水頭 亥姆霍茲速度分解定律意義： M0點(diǎn)領(lǐng)域的另一點(diǎn) M的速度 =M0點(diǎn)的速度 +（流 體旋轉(zhuǎn) +線應(yīng)變速率 +角變形速率）引起的相對速度 常用的流動分析方法： 1. 基本的物理定律（質(zhì)量守恒定律、牛頓運(yùn)動定律（動量和動量矩守恒定律）、熱力學(xué)第一定律（能量守恒定律）） 2. 系統(tǒng)和控制體分析法； 3. 微分與積分的方法； 4. 量綱分析法； 5. Visafree policy brings Chengdu biz, tourism boost. Making national headlines several times, Chengdu39。s 72hour visafree policy has attracted wide attention from both Chinese and foreign experts and businessmen since it took effect on Sept 1 last year. The program permits citizens from 51 countries and regions including the United States, Australia, Canada and Japan who have valid visas and flight tickets to a third country to spend three days in the city. The capital of Sichuan province is the first city in the western region of China to offer foreign tourists a threeday visa and the fourth nationwide to adopt the policy following Shanghai, Beijing and Guangzhou. Li Zhiyong, deputy dean of the tourism institute at Sichuan University, said the move contributes to a large increase in the number of overseas tourists and raises the city39。s level of internationalization. The policy will also bring direct economic revenue, Li said. Chengdu has many cultural legacies and is also a paradise for panda lovers with the world39。s largest breeding and research center. Three days are long enough for foreign visitors to visit those iconic tourist spots, he noted. The city is home to the remains of the Jin sha civilization that dates back more than 3,000 years as well as the Qing cheng Mountains and the Du jiang yan irrigation system.
公司管理相關(guān)推薦
鄂ICP備17016276號-1